...[T]en thousand River Commissions...cannot tame that lawless stream...cannot say to it, "Go here," or "Go there," and make it obey.

- Mark Twain

...[E]very atom that moves onward in the river...is controlled by laws as fixed and certain as those which direct the majestic march of the heavenly spheres....The engineer needs only to be assured that he does not ignore the existence of any of these laws, to feel positively certain of the result he aims at.

- James Buchanan Eads

The river man watched as thunderheads blew in from the west, throwing the valley of the Ohio in purple shade. Soon rain fell. Now after months of drought the river would rise, and Henry Shreve could go down the great Ohio to the greater river in the West, and begin the job no one thought he could do.

He was forty-four in the summer of 1829, thick in the shoulders and upper arms from his early years of excruciating labor, but thickening at the belt now, too. His brown hair was wavy, his eyes gray. He was given to long contemplative silences interspersed with bursts of creative energy. Shreve had first seen the Mississippi as a boy, in 1799. By that year Americans west of the Alleghenies were already sending prodigious amounts of farm produce, whiskey, and furs down the river to New Orleans by raft, barge, and keelboat. Gravity supplied all the power needed for the downstream trip. But to go upstream, crews had no choice but to pull and push the boats themselves. Tapping the potential of the inner continent demanded that someone figure a way to drive boats up the river as well as down.

Then in 1816 Henry Shreve designed a river-worthy steamboat and proved it could beat the current. That craft, with its shallow draft and high-built decks, revolutionized western transportation and made Shreve's name famous. He married happily, built and ran more steamboats, made money.

Yet for nearly ten years he devoted much of his time and considerable mental powers to an engineering problem that nearly all the river men of his generation believed insoluble. Why would he undertake this new errand in the wilderness -- a fool's errand, nearly everyone said, even for a man of Shreve's achievements?

Shreve left no record of his deepest motives. But surely he was driven by the same westward imperative that had driven his father, a veteran of Valley Forge, to carve a wilderness farm from the Allegheny forest, and his older half-brother to seek his fortune on the western rivers. The revolutionary generation had made the new land their own. Now Shreve's generation would pry the land open to extract the prizes that lay within, and they quickly learned that the richest prizes lay in the valley of the Mississippi River. There they found agricultural land as fine as any in the world and a waterway that connected the nation's midsection with the ocean trade routes. But using the river for transport would not be easy. And the job of claiming and safeguarding the land -- and the works of civilization they built on it -- would be harder still. For of all the natural adversaries greeting Americans on the new continent, the lower Mississippi River was the most dangerous and the least tractable.

"TEETH OF THE RIVER"

Long before Henry Shreve first boarded a flatboat, his countrymen realized the Mississippi and its tributaries comprised one of the world's great systems of navigable water. The main stream is really two rivers -- the upper Mississippi, which flows from snow-choked headwaters near Canada to the center of the continent; and the broader, more baffling lower Mississippi, which carries the waters of the upper river, the Missouri, and the Ohio to the sultry salt marshes of the Gulf of Mexico. Together, the Mississippi and all its tributaries form a fifteen-thousand-mile web of waterways stretching from present-day New York to Montana, through nearly half the lands of the continental forty-eight states. Its shallow valley is so broad, a traveler once said, that "a native tribe from its eastern rim of the Alleghenies might spend a generation migrating through it before sighting the Rockies that walled it on the west."

The river came to be called "Father of Waters," but in geological age it was barely a toddler, and a defiant one at that.

It sprang into being as the glaciers of the last Ice Age lumbered northward, trailing swampy streams that became the Ohio, the Missouri, and a hundred others. Where these streams joined and ran south to the ocean, they dug a groove through the soft slab of clay and sand that became the American South. Every year, every droplet of spring rain that fell upon much of the continent ran downhill in the direction of that groove -- the Mississippi's riverbed -- each rill carrying a microscopic load of organic material and sand. Coursing southward, the water scoured more soft earth from the banks and bottom and whisked it along. Below the points where the Missouri and Ohio joined the master stream, uncounted tons of dirt swirled in the water like muddy clouds. (Farmers would say it was too thick to drink and too thin to farm.) The water and its burden of sediment determined the river's ever-shifting geography, and the geography challenged the ingenuity of the Americans who settled on the banks.

They soon learned that the river, like a creature of myth, possessed the power to change its shape, and did so again and again. Wherever the current slows, especially on the inside curve of a bend, sediment falls to the bottom. There a sandbar forms. The bar nudges the oncoming current toward the opposite bank. That bank crumbles under the current's pressure, sending more sediment downstream, where it collects elsewhere as a new sandbar. Mile after mile, century after century, the river undulates in a crazy squiggle of curves and horseshoes.

This process of geological transformation handed Henry Shreve his great challenge. In his era the trees of the original North American forest still stood guard up and down the Mississippi. Wherever the current assaulted the banks, these old giants lost their footing, slid into the river, and floated downstream as dangerous snags. Some blundered into sandbars or islands, catching other snags and blocking the watercourse. Some wandered free, their bobbing limbs beckoning to rivermen in slow, sinister gestures of invitation. (These were called "sawyers," for the way they appeared to saw the surface.) The deadliest snags were called planters -- trees whose roots caught in the silt floor and stuck fast. More silt would pile against the roots, embedding the tree, its shaft pointing to the surface like a battering ram. When a steamboat struck a planter, the murderous effects were instantaneous -- "a sudden wrench, the rush of sucking water, a clanging of bells, terrified screams, and the current would sweep over another tragedy."

The snags had been falling into the Mississippi since the Mississippi began. The early French settlers at New Orleans had called them chicots -- "teeth of the river." By the 1820s, American surveyors counted 50,000 of them. And those were only the ones they could see. As steam traffic mounted, so did the damage and loss of life. Fear of snags slowed commerce. Military men, including Generals Andrew Jackson and William Henry Harrison, said snags impeded their mobility in the War of 1812 and the Indian campaigns. Pleas for federal action rose. In the summer of 1818, the influential Niles' Register reported: "Three steam boats have been lost in five months...in consequence of running foul of great trunks of trees....Will not the increased navigation of this mighty stream soon justify an attempt to clear it of such serious incumbrances -- or is it practicable to do it?"

That was the question: Did any effort to clear the Mississippi of 50,000 snags even stand a chance?

Henry Shreve believed so. As an owner of steamboats, he found the sodden driftwood hindering his every trip, costing him money and threatening the safety of passengers and crews. The great logs became a personal challenge, even a mild obsession. At home and on the river, he sketched plans for a strange new river craft.

Then, in 1824, the glowering South Carolina statesman John C. Calhoun, as secretary of war, invited river men to submit ideas for snag clearing. Shreve offered his plan for a twin-hulled steamer rigged with an apparatus for sawing off snags underwater and hauling them out with a manually operated windlass. Calhoun never responded. Yet no other river man produced a practical idea.

Soon a second plea issued from Washington. This time Shreve kept quiet, and the War Department hired John Bruce, a Kentuckian like Shreve, to clear all snags from the Ohio and the lower Mississippi for $65,000. Bruce tried his own twin-hulled design, failed, then attacked the Ohio snags with teams of men armed only with saws and chains. After two years they had barely begun on the Ohio, let alone the Mississippi, and Bruce's money was gone.

Under increasing pressure from the West, the new secretary of war, James Barbour, cast about for some new plan. He spoke to Calhoun, now John Quincy Adams's vice president, who recalled Shreve's ideas. Though Shreve was well-known as an Andrew Jackson man -- and thus a natural enemy of Adams, who had defeated Jackson for the presidency in 1824 -- the administration set aside its partisan reservations and hired Shreve as superintendent of western river improvements under the army engineers, at a salary of six dollars per day.

Shreve had to send a stream of beseeching letters before Washington would authorize construction of his snagboat for $12,000. Finally, after he reported success with a model -- "The machine is beautifully simple and most powerful in its operation and produces the effect intended in the most admirable manner" -- the army agreed to pay, but told Shreve that if his experiment failed, he would bear the cost himself.

At New Albany, Indiana, a few miles down the Ohio River from Louisville, Shreve's idea took on solid form. Two steamboat hulls 125 feet long lay side by side, each with a paddle wheel on its outer edge. Beams connecting the hulls supported an overhead pulley-and-windlass apparatus for lifting snags from the water. At the bow was a wedge-shaped beam made of heavy timber and sheathed in iron. This was the weapon Shreve would thrust at snags. He named the boat Heliopolis.

Few on the rivers believed it would succeed. Some even stooped to political sabotage. A fellow river captain wrote the War Department: "It is said that the present Superintendent has it in contemplation to construct a large and powerful steamboat, for the purpose of cutting out the snags, and pulling them out by the force of steam. Now, those projects are only calculated to get through the appropriation, without anything like the object contemplated. All machinery, whatever, whether used by lever or steam power is considered by persons who are well-acquainted with the Mississippi river navigation, as a useless expenditure of time and money." But other captains signed petitions on Shreve's behalf. They wanted action against the rotting obstacles, however unlikely the result.

In the spring of 1829, the Heliopolis was finished. But a drought had drained the Ohio to its lowest level in years, keeping Shreve in port. He waited. In mid-August heavy rains fell and the river swelled. The Heliopolis made its way down the Ohio, then the Mississippi, to Plum Point, Tennessee, a place studded with snags, one of the most dangerous places on the entire river. Shreve arrived at midnight on August 19.

In the morning, as he got ready, other boats stood at a distance, their crews expecting the first collision with a snag to jolt the snagboat's boilers into explosive fury. Shreve chose a planter and turned the boat toward it. The Heliopolis gathered speed and closed in. At full steam the iron wedge crunched into timber. The tree snapped. Windlasses whirled and chains clanked, and the planter emerged, dripping, from the brown depths. The trunk had broken several feet below the surface of the sandy bottom. In moments, Shreve's men sawed it into small pieces.

That fall Shreve roamed the western rivers. By 1830 his triumph was known throughout the country. "Capt. Shreve has perfectly succeeded in rendering about 300 miles of river as harmless as a mill-pond," one newspaper reported. A second snag boat was commissioned, then a third and fourth, all virtually identical to the Heliopolis. Soon the Ohio and Mississippi were all but free of snags, then the Arkansas. Finally, in his most remarkable achievement, Shreve cut through the immense log blockage of the Red River in Louisiana known as the Great Raft, 150 miles long, all the way to a place that would soon be called Shreveport. From Texas to Pennsylvania, the rivers were clear.

Of course, even a clear river is only as safe as its channel. Shreve's ingenious boats had made the river safe during normal seasons. But the Mississippi is capable of frightening departures from the normal.

AN ENDLESS WALL

[Y]ou hardly ever see the river, but the levee is always close by, a great green serpent running through woods, swamps, and farms, with towns nestling close to its slopes. The levee is unobtrusive, since its slope is green and gradual, but in fact it is immense -- higher and longer than the Great Wall of China, very likely the biggest thing that man has ever made....It was the principal human response to the titanic power of the great river.

-- Alan Lomax, The Land Where the Blues Began

A band of mosquito-ridden Spanish soldiers were the first people of European origin to see the Mississippi in flood. In 1543 they crossed a bewildering inland sea that drowned all but the tallest trees, and they paddled like hell to leave it behind.

What they saw was simply the lower Mississippi being its natural self. The river rises with the rains every spring and often spills out on the land. Through the millennia since the last Ice Age, the spreading floodwaters have dropped layer upon layer of sediment, the heaviest sediment nearest the river, thus creating a rich cake of soil up and down the banks. The land sloped away from these natural mounds and turned swampy, but under the swamps the land was highly fertile, too.

The French, who came a century and a half after the first Spanish explorers departed, weren't so easily scared off. They built a town, New Orleans, on the broad mound of sediment between the river and Lake Pontchartrain. To keep the spring high water out of their streets, they constructed a dike along the river. They called it a levée, from the verb lever, to raise. By 1727 it was three feet high, eighteen feet across the top, and a mile long. If they had known what Herculean labors they were setting in motion by building that little wall, they might have packed their bateaux and followed the Spanish. For one levee inevitably begat another levee, and so on ad infinitum.

This the Americans discovered soon after President Thomas Jefferson bought the vast, unexplored territory of Louisiana -- essentially the entire western drainage basin of the Mississippi -- from the French in 1803. They learned that if you built a three-foot-high levee on the east bank of the river, while on the west bank there was no levee, then the next flood crest would overflow the west bank. So the people on the west bank would build a six-foot levee and push the next flood back to you. The logic became obvious: Wherever people proposed to live year round, there must be levees.

At first, planters along the river bore the expense of building the mounds on their own land. But as it became clear that the levee was only as strong as its weakest section, and as costs mounted, levee districts were organized and given the power to raise taxes that would spread the financial burden among all those who benefited from the levee's protection. In some years, such as 1828 and 1844, high waters broke through the walls to flood farms and villages. But in most years the levees worked. They protected existing farmland and made it possible to drain and plant new farmland. More people came, and they depended on the levee, too. And so it went on both sides of the river, foot by foot and mile by mile.

By 1850 the costs were crushing. Under pressure, Washington bequeathed millions of acres of federal swamplands to the riverine states, which then sold the land to raise money to build more and better levees, which meant that still more swamps could be drained to make farms, and still more people depended on the levees.

As the levees became indispensable, their construction became more sophisticated. The early levee builders had simply piled dirt on the riverbank in long mounds filled with stumps and logs. A major high water could easily shove many of these mounds aside. Or the water, soaking the levee, would cause the stumps and logs to rot, leaving cavities that collapsed under pressure. Gradually, civil engineers learned the river's destructive tricks and how to combat them, and by 1880 they had developed a standard levee design.

First, workers would clear all debris from a wide ribbon of space, usually well back from the river itself. Down the middle of this space they dug a ditch three feet deep and three feet wide. They refilled the ditch with fresh dirt, then piled a mound of dirt on top of the dirt in the ditch. By this process they created one solid mass of material, some below ground and some above, with the ditch dirt anchoring the levee to the natural ground as the whole mass compacted and hardened. The river couldn't so easily push this anchored mass aside.

The levee was to be 3 feet taller than the presumed high-water maximum. The base at ground level was to be 5 to 7 feet across for every foot of vertical height. The levee should be as wide at the top as it was high. Thus, as the levee grew taller, it grew much broader. A levee just 7 feet high would be 7 feet wide at the top and 35 to 50 feet across at the base. After another ditch was dug to lure away the water that inevitably oozed through the structure, workers seeded the whole mound with Bermuda grass, which in time formed a tough, soddy seal that withstood high water far longer than exposed ground.

These rough engineering works were hardly perfect. Men had to patrol the levees to spot trouble, especially in spring. They looked for animals, even crawfish, digging tunnels through the mounds. They looked for sand boils, the little geysers that erupted when the river's colossal weight pushed jets of water under or through the levee, eroding it from within. And in flood times, the guards watched the river for men approaching by boat with explosives. If they blew a hole in your levee, inviting the river to destroy your land, they might save their own.

And the river did increasingly hold the power of destruction. For the levees were built on a paradox. The higher they rose, and the more continuous their line on both sides of the river, the more protection they afforded -- as long as they did not break. If they broke, their great height actually increased the risk that the ensuing floods would drown and destroy.

Why? Because untold millions of tons of spring floodwaters now stood much higher -- nearly forty feet high in some places -- than the ground on which the levees were built. When that much water stood so high above the land and then tore a hole, or "crevasse," in the levee, simple gravity would force the water to fall on the land with a force akin to Niagara Falls.

Engineers on the River

Whenever the levees failed, the people of the lower Mississippi begged the nation's engineers for solutions. But to tame the river the engineers had to understand it, and its behavior was nothing short of bizarre.

As John M. Barry wrote in Rising Tide, his comprehensive study of the control of the lower Mississippi and the 1927 flood, the river "moves south in layers and whorls, like an uncoiling rope made up of a multitude of discrete fibers, each one following an independent and unpredictable path, each one separately and together capable of snapping like a whip. It never has one current, one velocity. Even when the river is not in flood, one can sometimes see the surface in one spot one to two feet higher than the surface close by, while the water swirls about, as if trying to devour itself. Eddies of gigantic dimensions can develop, sometimes accompanied by great spiraling holes in the water." Where the watercourse bends, "the collision of river and earth...creates tremendous turbulence: currents can drive straight down to the bottom of the river, sucking at whatever lies on the surface, scouring out holes often several hundred feet deep."

The river's variables were many and they changed constantly. Heavy rainfall or collapsing banks could shatter months of careful observations. The shape of the riverbed's underwater cross section varied wildly from place to place. Tidal waters entering from the Gulf of Mexico affected the river's movements for many miles upriver. At flood stage the river behaved entirely differently than at low water. Levees that held a large high water might collapse under a lesser one. And hard as it was for the engineers to detect any predictability in the water itself, it was perhaps even harder to perceive rhyme or reason in the behavior of sediment -- how it moved at various depths, why it fell to the bottom where it did, how it affected the speed and direction of the current. Whenever one set of conditions seemed about to yield to sustained study and analysis, the river would blast those conditions to hell and make something wholly new and unknown.

In the mid-1800s, two schools of thought gradually emerged about what to do. Given the scarcity of dependable fact, it's hardly surprising that they seemed to be diametrical opposites.

One school argued that the river could be enlisted to dig itself a deeper bed, which would hold more water and thus prevent floods. The theory had its roots in the valley of the Po River in northern Italy. There, an engineer named Domenico Guglielmini (1655-1710) had theorized that if you built walls to confine an alluvial river such as the Po, you would force the river to rise. A higher river has a steeper slope to its outlet, and a steeper slope makes the river run faster. A faster river scrapes up more sediment from its bed. In short, a river confined within levees would dredge a deeper bed for itself, and thus carry more water in times of flood. The "levees-only" theory, as it was known, scored some successes in controlling floods in Europe, so it gained adherents in the Mississippi valley. Some even argued for closing off the Mississippi's natural outlets to increase the river's scouring power. But they had fierce opponents who believed levees were little more than a necessary evil.

The idea of the opponents of "levees-only" can be expressed by analogy to a kitchen sink. When someone closes the drain and turns on the faucet, water climbs up the walls of the sink. If no one opens the drain or turns off the faucet, the water overflows onto the floor. That is the nature of rivers, too, but no one can turn off the Mississippi. If you can't turn off the faucet and you don't want the floor to get wet, it doesn't make sense to build up the walls of the sink. It makes sense to open the drain.

To keep the Mississippi from flooding, the opponents of "levees-only" said, its drains must be kept open. Dredges should be employed to keep silt out of the river's natural outlets, such as the Atchafalaya River and other Louisiana bayous, so they could better absorb floodwaters. Reservoirs should be built on tributaries to hold floodwaters out of the main river. And most important, artificial outlets should be built to allow floodwaters to spill off into alternative routes to the Gulf. These ideas comprised the "outlets" theory of flood control.

To resolve the argument, Congress decided in 1850 that a major federal survey was needed to wrest the secrets of flood control from the lower Mississippi once and for all. Because this was to be one of the great scientific undertakings of the era, leaders of the Army Corps of Engineers assumed the survey would be theirs. After all, the profession of engineering in America had been virtually synonymous with the corps for half a century; few influential engineers had been trained outside West Point. But as the industrial revolution spread, engineers outside the military were rising in numbers and influence, and they demanded the Mississippi survey be assigned to one of their own. So President Millard Fillmore simply split the $50,000 appropriation in half and told the army to do one survey and the civilians another.

The civilian effort fell to Charles Ellet. One of the first American engineers to spurn West Point, Ellet took his training at the more scientific école des Ponts et Chaussées, in Paris. Handsome, brilliant, and brave to the point of foolhardiness -- he was the first person ever to cross the gorge at Niagara Falls -- Ellet commanded respect. He compiled his report in under two years. Short on data but long on vision, the report called levees-only "a delusive hope, and most dangerous to indulge, because it encourages a false security....The water is supplied by nature, but its height is increased by man. This cause is the extension of the levees." Instead, Ellet called for the dredging of natural outlets and the construction of artificial ones. For a few years in the 1850s, his work was celebrated as the authoritative statement on the Mississippi.

His rival in the corps of engineers was Andrew Atkinson Humphreys, a driven and driving man who, despite his army background, approached the study of the river with far greater scientific tenacity than Ellet. This meant that he took longer than Ellet. He chased every last fact, tested every theory. He became so consumed by his task that he suffered a nervous breakdown, lost his funding, and had to set the work aside for several years. But in the summer of 1861, amid the first clashes of Union and Confederate armies, Humphreys completed his survey. It became the most influential scientific study of the Mississippi ever written.

Humphreys was no more persuaded by the levees-only theorists than Ellet had been. Observable facts proved Guglielmini's idea that levees would lead to a deeper river "totally erroneous," Humphreys said, and that closing natural outlets would be "disastrous."

But Humphreys was equally dismissive of the outlets theory. He said flood reservoirs on the Mississippi's tributaries would not work. He said artificial outlets, though they would indeed lower the river, would be too expensive relative to the value of the property they would protect. And, he said, outlets posed a grave, heretofore unforeseen danger. In a great flood, the main stream of the Mississippi might shift entirely to the new outlet, leaving the old channel, with all its human settlements, an isolated backwater. To guard against floods, he said, the nation would have to make do with strong levees. They would not make the river deeper, but they "may be relied upon for protecting all the alluvial bottom lands liable to inundation."

The Civil War distracted all attention from river hydrology. But it decided the winner of the great river debate. Charles Ellet was killed on a Union battering ram. Andrew Humphreys not only survived the war but achieved renown as a field commander at Fredericksburg and Gettysburg. To reward his war service and his river survey, he was named chief engineer of the army in 1866.

Ellet's case for outlets faded away, and Humphreys's views prevailed. Unfortunately, the nuances of his massive report were not entirely understood. People understood him when he said levees would do the job. But many overlooked his dismissal of the key idea of levees-only -- that levees would make the river deeper. So the levees-only theory lingered in the public mind. And in the 1870s it appeared to draw new vitality from the extraordinary achievement of a brilliant, disciplined, austere man who was regarded as the nation's greatest engineer, James Buchanan Eads.

Mr. Eads at the Passes

Eads had learned the Mississippi's strange ways as no man ever had. In 1838, as a steamboat man barely out of his teens, he had spotted opportunity in the hundreds of shipwrecks sent to the river bottom by fires, boiler explosions, and Henry Shreve's snags. Some said the river's crazy currents and shifting floor made it impossible to salvage the wrecks. Eads disagreed. He built a salvage vessel much like Shreve's snagboats. To locate lost cargos in the silt-laden water, he made some three hundred descents to the bottom in dangerous diving bells. About one dive he wrote:

"The sand was drifting like a dense snowstorm at the bottom....At sixty-five feet below the surface I found the bed of the river, for at least three feet in depth, a moving mass and so unstable that, in endeavoring to find a footing on it beneath my bell, my feet penetrated through it until I could feel, although standing erect, the sand rushing past my hands, driven by a current apparently as rapid as that on the surface. I could discover the sand in motion at least two feet below the surface of the bottom, and moving with a velocity diminishing in proportion to its depth."

These intimate explorations provided all the data that Eads's acute mind needed to master the river in various ways. He made a fortune in salvage. During the Civil War he constructed ironclad warships for the Union navy. After the war, at St. Louis, he built the first bridge over the Mississippi, proving the value of the new experimental metal, steel.

Even before his bridge was complete, Eads, now fifty-five years old, tackled a still greater challenge, this one in the deepest South, where the Mississippi splits into three short branches, or "passes," and flows into the Gulf of Mexico. What he accomplished there had nothing to do directly with flood control. But it would profoundly affect the flood control debate.

Here at the river's mouth lay muddy lumps of geological goo from every acre of land between the Pennsylvania coal fields and the Yellowstone wilderness. These great sandbars were growing noticeably larger by the year, slowing the passage of ships in and out of the river and threatening to block them entirely.

The sandbars were the natural product of the river going about its business. Every day the current dropped more sediment at the mouth. In time, when there was more sediment than water, the river in its nonchalance would simply spill off in some new route to the Gulf. It had done so for eons.

But Americans had committed themselves to this route, lining it with cities and farms and port facilities. They couldn't wait for a century as the Mississippi slowly changed its mind. The sandbars threatened the prosperity of the entire valley, even the nation. In 1859, a visiting business delegation counted three ships stuck on sandbars, thirty-five ships waiting upstream to get into the Gulf, and seventeen waiting in the Gulf to get into the river. Action was essential.

The corps of engineers failed in one attempt after another to get rid of the bars. In desperation, the New Orleans Chamber of Commerce demanded that a canal be dug to bypass the blockage altogether. The corps agreed. Ships still would have to stand in line, because the canal would be wide enough for only one ship at a time, but at eighteen feet it would be deep enough for most ships. It would cost $13 million. The canal's champion was the corps's chief engineer, General Andrew Humphreys.

With the canal plan all but settled, James Eads entered the debate. Nearly forty years earlier, Eads had been working in St. Louis when huge sandbars rose up between the city's waterfront and the river. Eads watched as a young army engineer carried out an ingenious plan. At a strategic point in the river, the officer constructed a great pier, or jetty. The jetty guided the river's currents directly against the sandbars. The sandbars washed away and the threat to the city disappeared. The young officer's name was Robert E. Lee.

Eads had not forgotten. Since then, he had seen jetties clear out the mouths of European rivers, and he had only contempt for the corps's planned canal. So Eads proposed to build a pair of parallel jetties in the southwest pass of the Mississippi. The jetties, he said, would squeeze the river's spreading currents like the nozzle of a firehose and blast the sandbars into the Gulf. He promised that his channel would achieve a substantially greater depth than the corps was proposing for its canal. And he said it would be wide enough that ocean-going ships could pass each other in and out of the river. He could do the job for just $10 million, he said, and the government wouldn't have to pay until he delivered.

Humphreys and a phalanx of critics lashed back. All through the spring and summer of 1874, Eads and Humphreys battled for support in Congress, lobbying, cajoling, arguing, lecturing. Newspapers across the country covered the fight. Civilian engineers supported Eads, hoping to take the corps of engineers down a peg. Humphreys had the backing of New Orleans's business elite. These men distrusted "strangers" like Eads, "who can know nothing of our inexorable enemy," the river, which would teach such upstarts "modesty and humility in the presence of the gigantic torrent."

"I am sure I have not learned 'modesty and humility in the presence of the gigantic torrent,'" retorted Eads, who had spent far more time in the Mississippi -- literally -- than any New Orleans tycoon. "Nor do I believe that it can be controlled by modesty and humility."

After more months of study, a committee of experts appointed by Congress recommended jetties by a vote of six to one. But General Humphreys devised a trap. His friends in Congress insisted that Eads switch his plan to the shallower South Pass -- this would be cheaper but more difficult -- and when Eads argued, they said he was trying to extract excessive profits from the deal. Eads was forced to accept the South Pass plan.

Defiant, he promised victory.

"If the profession of an engineer were not based upon exact science, I might tremble for the result," he said. "But every atom that moves onward in the river, from the moment it leaves its home amid crystal springs or mountain snows...until it is finally lost in the vast waters of the gulf, is controlled by laws as fixed and certain as those which direct the heavenly bodies....I therefore undertake the work based upon the constant ordinances of God Himself; and [if] he will spare my life and faculties for two years more, I will give the Mississippi River...a deep, open, safe and permanent outlet to the sea."

In May 1875, Eads set off from New Orleans with a fleet of barges, tugboats, steam launches, and floating pile drivers, all bound for the low-lying landscape where little but whispering grasses and fishermen's huts marked the presence of land in a wilderness of water and sky. They found the sand-clogged South Pass only eight feet deep.

First Eads's men built a settlement of white cottages and plank walks, which they called Port Eads. Then they drove two lines of piles -- log posts like telephone poles -- deep into the river bottom. These parallel lines of piles stretched about two miles long, about a thousand feet apart. They marked the lines of the two jetties.

Eads had dropped off some of his crews forty miles upriver, where they waded among water moccasins and leeches to cut thousands of young willows. They sent the trees by barge to Port Eads. There other crews heaped the trees in pine frames to make giant, brushy "mattresses," each 100 feet long, 35 to 60 feet wide, and 2 feet thick. Dutch dike-builders had invented these odd contraptions, but Eads's method cut the time it took to build one from two days to two hours. When each mattress was finished, a tugboat towed it to the jetty pilings, where men dumped rocky rubble on it, forcing it to sink. Then another mattress was sunk on top of the first, and so on until the mattresses stood up to sixteen layers deep.

Section by section, these towers of sunken willow mattresses formed the jetties' walls -- or, more accurately, they formed a dense scaffolding for the walls. The river completed the job, just as Eads had foreseen. Gradually the passing currents deposited sediment on and among the mattresses, filling in the jetties until they were as solid as concrete.

But before he could prove the jetties were deepening the channel, Eads ran short of funds. Humphreys's men on the scene conducted their own depth soundings and claimed the channel was only 12 feet deep -- far short of the 30-foot requirement -- and that the jetties had created "the nucleus of a new bar" farther out in the Gulf. Eads's own soundings showed the channel was at least 16 feet deep already, and that the sandbar was a mirage. But federal officials refused to issue the official report of soundings, or to order new ones. Without this official proof Eads would be unable to attract new investors, and his whole endeavor would collapse.

Then, on May 12, 1876, the big oceangoing steamer Hudson, with a draft of fourteen feet, seven inches, approached the mouth of the river from the Gulf. Its captain was E. V. Gager, a friend of Eads and a supporter of the jetty plan, who had said he hoped his ship would be first through the new channel. Learning what was at stake, Gager, despite a falling tide, ordered his vessel onward.

James Eads had told him the channel was sixteen feet deep. So Captain Gager ordered his engines put to full steam. Pushing a half-crown of white foam before her, the Hudson entered the channel...kept moving...steamed through.

"Captain Gager...greatly assisted the enterprise in one of its darkest hours," Eads's chief assistant wrote later, "for the stubborn facts brought out by his brave action could not be gainsaid."

Investors returned and the project was saved. By that fall the channel's depth reached 20 feet. In 1879 it was 30 feet. Soundings found no new sandbar rising in the Gulf of Mexico. In the five years after Eads began, the tonnage of cargo moving from St. Louis through New Orleans to Europe increased sixty-six fold.

"Human patience and courage and industry, backed by an indomitable and untiring will, and informed and directed by human skill, have applied the force of nature to the accomplishment of an end too vast for mere artificial agencies," a New Orleans editorialist wrote. "Man has used the tremendous river which uncontrolled has been its own oppressor and imprisoner, and has now become its own liberator and saviour."

THE WATER RISES

Eads had made the Mississippi do his bidding with a work of engineering that became famous around the world. That was good and bad. For some people now lost a little of that "humility in the presence of the gigantic torrent" that the Mississippi demanded. They believed Eads's jetties confirmed the levees-only theory of flood control.

Eads himself believed nothing of the kind. He said levees would never cause an appreciable deepening of the riverbed because they stood back from the banks, and confined the river only in flood season. Jetties, by contrast, were built right in the river. They didn't merely hold the current off the land. They concentrated it, increasing its power. And they performed this feat year round. Nonetheless, people now thought levees, like jetties, would force the river to scour a deeper channel, which in turn would mean fewer floods.

Levees-only offered a political advantage, too. In the 1870s and 1880s, the levee system lay in ruins. In 1865 the corps of engineers had counted fifty-nine breaks in the levees in the Mississippi Delta alone. Demolition teams under General Ulysses S. Grant had done a good deal of the destruction. The river's natural powers of erosion, plus great floods in 1867 and 1874, did more. And the Civil War had impoverished the states of the lower Mississippi. Few levee districts could afford to do their work well.

Since the days of Jefferson and Jackson, Americans had believed that the Constitution forbade federal spending on projects that helped only one state or region. If Louisiana and Mississippi wanted protection from floods, the argument went, they would have to pay for it themselves. But interstate commerce was another matter. Everyone agreed that warranted federal help. If one argued that levees would aid interstate commerce by keeping the river deep and stable, one could persuade Washington to pay a big share of the bill. Flood control would be just an incidental benefit of better levees. On the other hand, the only argument one could make for floodways and reservoirs was in the name of flood control. If that was what you wanted, you had to pay for it yourself. Besides, the levees-only theorists said, reservoirs and spillways would only diminish the supposed scouring power of the river.

By 1879, it was clear that levee-building must be systematized and strengthened. So Congress -- in a delicate act of reconciling constitutional activists and conservatives, army and civilian engineers -- gave the job to a new Mississippi River Commission. Its powers were deliberately vague. Its membership was split between soldiers and civilians, but the soldiers soon gained the upper hand. They supervised a vast program of levee improvements, with new standards for construction and height. The levees rose higher and stronger.

But so did the river, contrary to the levees-only theory. By 1890, when yet another major flood inundated the valley, it was obvious the levees were not forcing the river to dredge itself a deeper bed. But the levees did offer short-term protection against devastation. Money was limited.

Better to spend it on bigger levees, which promised safety for next year, than on expensive and experimental works -- such as jetties or outlets -- that would take many years to produce results if they worked at all.

By the 1920s the levees stood unbroken from the mouth of the Ohio to the Gulf, a thousand miles on either side, three and four stories high, more than 400,000 cubic yards of earth for every mile of levee. Every spring, the rebellious river stood up on top of the land, running down the continent between two walls built by the hand of man.

The Great Flood

Late in the summer of 1926, storms drenched the Midwest. The rivers rose to levels unheard of so late in the year. The rain abated, then began again in January 1927, much earlier than the usual spring rains, in a wave of cataclysmic storms. Water rose so high at the confluence of the Ohio and Mississippi that the Ohio turned around and flowed upstream.

In April the rain grew worse -- eighteen inches on Good Friday in New Orleans, with similar inundations across the Midwest and South. The next day, April 16, the Mississippi broke through at Dorena, Missouri, flooding 175,000 acres. It was the first crevasse ever in a levee built to federal specifications. To steady a shaking railroad bridge over the Arkansas River, engineers parked a coal train on it. The trembling became so violent the coal erupted in flame, and the bridge collapsed, train and all, into the rushing water.

About 6:30 A.M. on Thursday, April 21, a stream of water one foot deep and two feet wide began to spurt through a low spot in the levee at Mounds Landing, Mississippi. Foremen held laborers at the spot at gunpoint, but the sandbags they threw in the hole spun away in the widening torrent. At 8 A.M. a massive chunk of the levee crumpled -- it "just seemed to move inward as if 100 feet of it was pushed out by the river," a witness said -- and the water rushed through, carrying scores of men to their deaths. People heard the sound miles away.

A virtual tidal wave surged east and south across the Mississippi Delta, its volume double that of Niagara Falls at flood stage. The water spread 50 miles to the east and 100 miles downriver at a depth of 20 feet, forcing nearly 200,000 people to flee. It struck a ridge of hills and turned south, rejoined the Mississippi near Vicksburg, and punched out the levee on the opposite side of the river, at Cabin Teele, Louisiana. From there the water rolled over a belt of land 50 miles wide, joining more rivers already in flood.

Mounds Landing and Cabin Teele were only the worst crevasses. There were 120 in all, 42 of them major. In some places the Mississippi stretched 100 miles wide. "For mile after mile all the land in view was the tops of the levees, to which thousands had fled for safety," wrote a reporter who crossed the inland sea in an airplane. "In places the tops of giant cypress and oak trees still swayed in the breeze, the only green spots in the picture."

All through early April, the 419,000 people of New Orleans had waited. The levees had protected the city from floods since 1849. Some students of the river now believed the immense power of the approaching flood crests actually worked to the city's advantage -- the water couldn't help but break through levees upriver. That would relieve the danger to the city. But the rising water carried its own logic, and thousands fled for higher ground.

During the Good Friday storm, a self-appointed committee of businessmen, most of them bankers, decided they would take no risks. The levee must be dynamited to bring down the level of the river. The river would have to be unleashed. They could break the levee upriver from the city, where much valuable property would be wrecked, or downriver, where the land and people were poor. They chose the latter. The mayor, the governor, the Mississippi River Commission, the chief engineer of the army, and the secretary of war assented. (Secretary of Commerce Herbert Hoover, supervising the flood relief operation and preparing to run for president, refused to add his approval and absolved himself of any responsibility for the decision.) Ten thousand residents of two marshy parishes between New Orleans and the Gulf -- St. Bernard and Plaquemines -- were warned to evacuate their homes. On April 29, thirteen miles below New Orleans, demolitionists blasted a hole in the levee at a place called Caernarvon, and the downriver parishes were flooded. Their losses made up only a fraction of the total in this greatest of all U.S. floods: 17 million acres inundated in seven states; $100 million in lost crops; 160,000 flooded homes; 250 to 500 people killed.

As it turned out, the deliberate destruction of the levee at Caernarvon was unnecessary. The next day, the river cut a new crevasse north of New Orleans, eliminating any danger to the city. But the Caernarvon explosions signaled official recognition of a truth that rogue levee dynamiters had sensed for decades. Artificial spillways lowered floodwaters. The policy of levees-only made floodwaters more destructive.

"The River Needs More Room"

As the slimy, stinking fields of the flood region slowly dried in the late summer and fall of 1927, engineers motored from crevasse to crevasse, looking at the broken levees and wondering at the river's power. The flood had been the worst natural disaster in the nation's history. A great debate arose over how to prevent a repetition.

Seated at his desk in the War Department in Washington, D.C., General Edgar Jadwin examined his data through strong spectacles. His eyes were weak, but at least they were fresh. Jadwin had been chief of the corps of engineers only ten months when the flood occurred; before that he had worked on more harbors than rivers.

At sixty he was brainy, small, and a bit frail. He was fiercely defensive of the engineers. But he did not have to overcome a career-long devotion to levees-only, as did veterans of the lost war against the Mississippi.

Finally Jadwin declared: "The river needs more room, which should be given to it laterally rather than vertically."

These words were not just the death knell of levees-only. They represented a radical change in belief. Americans could not simply make the river do whatever they wished. They must recognize its own implacable will and try to negotiate a compromise.

Under the Jadwin Plan, as it became known, levees would be repaired, strengthened, moved farther back from the river, and in some cases raised. But they would not be built to levels any higher than could safely contain the river. Waters above that safe level would be allowed to spill off through what were essentially manmade crevasses and manmade flood channels. The visionary engineer Charles Ellet, sixty-six years in his grave, would have his outlets at last.

Jadwin said his plan delivered "the maximum of benefits for the minimum of costs." Some minimum. It was the most expensive domestic legislation in U.S. history to date (about $300 million, and that was just start-up funding). It formed the foundation of all efforts to control the Mississippi for the rest of the century and beyond. It established a giant precedent for federal intervention in local and regional problems. And it helped elect a president: Herbert Hoover's 1928 campaign was based in part on his widely touted success in helping the river's victims in 1927, and on his support for federal action against floods.

The corps set off on a ponderous race against the yearly threat of another terrible flood. Year by year the work proceeded, unslowed even by the Great Depression.

The engineers designed their first project in the realm of nightmares. They combined history's worst flood statistics into a hypothetical "Project Flood" -- the greatest snowmelts in the upper valley, the worst rainfalls ever, simultaneous storms in distant parts of the Mississippi basin that would swell the tributaries to historic heights. These conditions, the corps said, would produce a flood 29 percent worse than 1927. All new works would be judged by their ability to protect the valley from "Project Flood."

At Birds Point, Missouri, where the Ohio tumbles into the Mississippi, the corps built a floodway five miles wide and sixty-five miles long to bypass a chokehold where there isn't enough riverbed to bear the combined flow of the Mississippi and Ohio in flood. A low, "fuse-plug" levee was built as a gate to the floodway. Only a major flood would blow out the fuse plug. Water would then flow into the floodway, run south, and rejoin the main current where the channel widens near New Madrid.

If floodways had been Ellet's pet idea, the corps borrowed other theories from James Eads. They built dikes at key points to stabilize the current. Between the mouth of the Arkansas and the mouth of the Red, they dug a straight path through a tortuous series of horseshoe bends, shortening the river by some 150 miles. (The longer the river, the more friction the water encounters along the banks. Friction slows the current and forces the river to rise higher on the levees.) These "cut-offs" were so successful they eliminated the need for an entire additional floodway.

Thirty miles above New Orleans, at a place called Bonnet Carré, the Mississippi had blown crevasses in the east bank levee again and again, streaming across seven miles of field and semitropical swamp to reach Lake Pontchartrain, a natural outlet to the Gulf of Mexico. Since 1816 people had been saying it made sense to let the river have its way here. The 1927 flood demolished opposition to the idea, and a spillway at Bonnet Carré was incorporated in the Jadwin Plan.

Using a giant laboratory model to test their plans, corps engineers designed a spillway that closely resembled an irrigation dam. This would not be a fuse-plug structure like Birds Point, designed to give way under the pressure of high water. Instead, engineers would carefully control the water flowing through it. Set back from the river, the spillway would run parallel to the riverbank for a mile and a half, with some 350 gates made of rough-hewn timbers called "needles." When a dangerous flood crest approached, cranes could pull needles up and out of the spillway -- as many or as few as necessary. These gates, once open, would skim the crest off the river.

But that carried its own dangers. Floodwaters would plunge through the gates with monumental force, gouging a canyon in the earth. So engineers found ways to calm the water down. On the side of the spillway away from the river, they laid a broad, low apron of concrete called a stilling basin. Here the water would crash into a big belt of triangular baffles that looked like waist-high dragon's teeth. These would dissipate the water's energy without blocking the flow. Beyond the baffles, the water would cascade onto a concrete mat that resembled a giant waffle. Its channels would further subdue the flow, and the water, robbed of its power to destroy, would run more or less placidly down the seven-mile slope to Lake Pontchartrain.

By early 1931 constructions teams finished the spillway. It was a structure to overwhelm the eyes; one could see the whole thing only from the air. Then they built bridges to carry two rail lines and a highway over the long floodway to the lake. Finally they raised a fuse-plug levee at the edge of the Mississippi, across the spillway's front, and covered it with Bermuda grass sod.

In December 1936 the entire structure was declared complete. By Christmas it was raining in torrents up and down the Mississippi valley. The annual high waters had spared the valley for ten years. But now the sod on the spillway levee would not take root before Bonnet Carré, and the rest of the Jadwin Plan, met its first test.

Soon a flow of 1.85 million cubic feet per second was recorded on the Ohio at Cairo, a spectacular high water. The engineers of the corps watched intently as the water surged against the new fuse-plug levee at Birds Point. When it failed to break, they dynamited it. That saved Cairo. As the crest moved south it caused small floods in backwater regions, but the strengthened levees on the main river held.

At Natchez, Mississippi, two hundred miles north of New Orleans, the flood gauge recorded its highest level ever. The same thing happened at Carrollton. That was the official trip-hammer for Bonnet Carré. The corps gave the word.

On February 18, 1937, with crowds watching, the cranes atop the spillway hoisted timber needles out of 285 of the 350 bays. Water rushed into the stilling basin and exploded through the baffles. Surging down the floodway toward the lake, the tide wrenched trees from the soil. Yet even that degree of force lay within the margin of safety. For one week, then two, the Carrollton gauge stayed steady, and New Orleans stayed dry. By March 7 the river was falling, and the corps began to reinsert the needles. Nine days later the spillway was closed.

The 1937 high water was not the Project Flood. But it was high enough to prove Bonnet Carré a signal success, and to show that the Mississippi might tolerate man's effort at a compromise. Not a single levee on the lower Mississippi failed in the 1937 flood, nor has any failed since.

A PATIENT RIVAL

If the Mississippi is a toddler in geological age, the Atchafalaya (uh-CHAFF-uh-LIE-uh), which connects to the Mississippi via a manmade waterway some 120 air miles northwest of New Orleans, is a newborn infant. It emerged from the swamp in the 1400s, carrying water from a horseshoe bend in the Mississippi (later called Turnbull's Bend) through a jungle labyrinth to the Gulf. To complicate the landscape, the Red River emptied into Turnbull's Bend a few miles north of the Atchafalaya. To help steamboat traffic, Henry Shreve dredged a cut-off canal through Turnbull's Bend in 1831. But one seven-mile arm of the bend -- soon called Old River by the locals -- remained to connect the Mississippi to the Atchafalaya.

The Atchafalaya is what geologists called a "distributary" river, meaning it carries water out of a larger stream. But a distributary can become a trickster and a thief. As the main stream rises atop its floor of silt, it sends more and more runoff spilling down the distributary. That runoff water gradually digs the distributary a deeper bed. In time, the distributary offers a deeper, steeper outlet to the sea. One big flood and the main stream may change its mind entirely. Suddenly the old channel is abandoned and the river is following the distributary's path to the ocean.

Over the eons this has happened repeatedly at the Mississippi's mouth. At least five now quiet bayous have all served their time as the main channel. The last shift occurred about A.D. 1000. If the Atchafalaya were to capture the Mississippi now, the Port of New Orleans, one of the world's busiest, and a multibillion-dollar belt of riverfront industry would be stranded on a brook.

River engineers saw this coming. Just after the 1927 flood, Colonel Charles Potter, president of the Mississippi River Commission, looked over the big river and its eager distributary and said the Mississippi was "just itching to go that way."

But the corps of engineers could hardly wall off the Atchafalaya, which was by far the most important outlet envisioned in the Jadwin Plan, much bigger even than Bonnet Carré. Plug the Atchafalaya and you not only devastate the fisheries and Cajun communities that depend on it for water, you also doom New Orleans in the next great flood. Yet every gallon of water spilling into the Atchafalaya dug its bed a little deeper and raised the likelihood of an eventual shift. By 1950, geologists said the slope of the Atchafalaya's path to the Gulf had become three times steeper than the Mississippi's current channel. The river, they said, would certainly shift from one to the other by 1975.

So the corps constructed another compromise. Earthmovers dug a new, seven-mile-long channel -- a new Old River -- between the Mississippi and the Atchafalaya. Across this channel the corps built a 566-foot version of the Bonnet Carré spillway. They called it the Old River Control Structure, usually shortened simply to "Old River Control." Engineers raised its gates just high enough to allow 30 percent of the Mississippi to enter the Atchafalaya. That was judged to be enough but not too much. In the Atchafalaya swamps, the corps constructed a system of floodways, chiefly the West Atchafalaya Floodway and, thirty miles to the south, the Morganza Floodway. Then, in 1963, the engineers blocked the old Old River, opened the new one, and watched water cascade through the carefully calibrated gates of Old River Control.

Through the 1950s, '60s, and early '70s, the Mississippi cooperated. The spring high waters were manageable.

Early in 1973, major storms raised the Missouri and the Tennessee to towering levels. The crest approached.

"This is not a routine high water," General Charles Noble, chief engineer of the corps's Lower Mississippi Valley Division, warned. "We are confronted with river conditions which, if not controlled, could cause more loss of life and property than this valley experienced in the 1927 flood."

Corps engineers watched the water pound through Old River Control. On April 8, for only the fourth time in its history, they opened the Bonnet Carré spillway downriver. Yet people standing on the 200,000-ton structure at Old River felt it shake.

As the journalist John McPhee told it, a fisherman came into the office of LeRoy Dugas, who manned the controls at Old River, and asked: "Is that south wall supposed to be moving like that?"

"What do you mean?" Dugas asked.

"On the control structure," the man said, "a wall on the other side is moving."

"No," Dugas replied. "It's not supposed to be moving."

Soon that wall gave way and crumpled into the Mississippi. On the Old River side of the structure, the water seized seven-ton boulders and hurled them downstream. Unseen below the roiling surface, mad currents were digging a hole the size and shape of a football stadium, and scouring cavities under the structure itself.

The corps waited a little while longer, then for the first time opened the gates of the new spillway downriver at Morganza.

Old River Control held -- barely. If it had collapsed, engineers believe 70 percent of the Mississippi would have run down the Atchafalaya slope. The struggle to keep the river in its old channel would have been lost.

Humility and Ingenuity

Scientists at Louisiana State University declared in 1980 that a shift in the Mississippi's course remained "simply a matter of time." But the people who lead the U.S. Army Corps of Engineers are professional soldiers. They do what their country tells them to do, whatever the odds, and their country has told them to keep the lower Mississippi where it is. So in the wake of the great scare of 1973, they went back to work at Old River.

Corps workmen drilled holes through the damaged control structure and pumped truckloads of cement grout into the cavities underneath. Into the cavernous craters just beyond the structure, they dumped 185,000 tons of rock. That was enough to hold the structure in place, even when another major flood rolled through in 1983. A few hundred yards away, the corps built an Old River Auxiliary Control Structure. Costing nearly as much as the original expenditure for the entire Jadwin Plan, it comprised 7 towers and 6 gates, each 62 feet wide.

"I was asked, when I was testifying before Congress about the auxiliary structure at Old River, if this improvement would be all that was ever needed there," recalled Fred Bayley, former director of the corps's engineering division for the Lower Mississippi Valley District. "And my reply was, 'No, sir.' And the next question was, 'Well, what will be the next thing?' I said, 'I don't know, but with the system we're living in out here, there will be something, and that you can count on and that you must ever be ready for.'"

Corps scientists sought new approaches to their great problem. They turned their attention to a phenomenon that James Eads had discovered firsthand more than a century earlier, under a diving bell -- the sand that "drifted like a dense snowstorm at the bottom." Sediment, after all, was the root of the problem. There was too much in the Mississippi and not enough in the Atchafalaya. If a lot of it could be moved from the former to the latter, the fatal percentages might shift back in the Mississippi's favor.

So a continuous dredging program was undertaken at Old River. Sand is scooped from the Mississippi's silt load and dumped into the channel that flows to the Atchafalaya. No one knows whether it will be enough. "Mother Nature doesn't holler back at you that quick," says a corps hydrologist. When that message comes, the corps will be listening closely. They know, as James Eads said, that "modesty and humility" will not control the river. But they have learned that a little humility is wise where the Mississippi is concerned.

When people came to live by the Mississippi, the struggle to control it became inevitable. Only nomads could live there if the river ran free, and Americans did not intend to be nomads. It may be true, as a historian of the corps of engineers once observed, that in the Mississippi valley, "nature might reasonably have asked a few more eons to finish a work of creation that was incomplete." But Americans are impatient. They would just as soon finish Creation on their own.

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Chapter One: The Lower Mississippi

...[T]en thousand River Commissions...cannot tame that lawless stream...cannot say to it, "Go here," or "Go there," and make it obey.

- Mark Twain

...[E]very atom that moves onward in the river...is controlled by laws as fixed and certain as those which direct the majestic march of the heavenly spheres....The engineer needs only to be assured that he does not ignore the existence of any of these laws, to feel positively certain of the result he aims at.

- James Buchanan Eads

The river man watched as thunderheads blew in from the west, throwing the valley of the Ohio in purple shade. Soon rain fell. Now after months of drought the river would rise, and Henry Shreve could go down the great Ohio to the greater river in the West, and begin the job no one thought he could do.

He was forty-four in the summer of 1829, thick in the shoulders and upper arms from his early years of excruciating labor, but thickening at the belt now, too. His brown hair was wavy, his eyes gray. He was given to long contemplative silences interspersed with bursts of creative energy. Shreve had first seen the Mississippi as a boy, in 1799. By that year Americans west of the Alleghenies were already sending prodigious amounts of farm produce, whiskey, and furs down the river to New Orleans by raft, barge, and keelboat. Gravity supplied all the power needed for the downstream trip. But to go upstream, crews had no choice but to pull and push the boats themselves. Tapping the potential of the inner continent demanded that someone figure a way to drive boats up the river as well as down.

Then in 1816 Henry Shreve designed a river-worthy steamboat and proved it could beat the current. That craft, with its shallow draft and high-built decks, revolutionized western transportation and made Shreve's name famous. He married happily, built and ran more steamboats, made money.

Yet for nearly ten years he devoted much of his time and considerable mental powers to an engineering problem that nearly all the river men of his generation believed insoluble. Why would he undertake this new errand in the wilderness -- a fool's errand, nearly everyone said, even for a man of Shreve's achievements?

Shreve left no record of his deepest motives. But surely he was driven by the same westward imperative that had driven his father, a veteran of Valley Forge, to carve a wilderness farm from the Allegheny forest, and his older half-brother to seek his fortune on the western rivers. The revolutionary generation had made the new land their own. Now Shreve's generation would pry the land open to extract the prizes that lay within, and they quickly learned that the richest prizes lay in the valley of the Mississippi River. There they found agricultural land as fine as any in the world and a waterway that connected the nation's midsection with the ocean trade routes. But using the river for transport would not be easy. And the job of claiming and safeguarding the land -- and the works of civilization they built on it -- would be harder still. For of all the natural adversaries greeting Americans on the new continent, the lower Mississippi River was the most dangerous and the least tractable.

"TEETH OF THE RIVER"

Long before Henry Shreve first boarded a flatboat, his countrymen realized the Mississippi and its tributaries comprised one of the world's great systems of navigable water. The main stream is really two rivers -- the upper Mississippi, which flows from snow-choked headwaters near Canada to the center of the continent; and the broader, more baffling lower Mississippi, which carries the waters of the upper river, the Missouri, and the Ohio to the sultry salt marshes of the Gulf of Mexico. Together, the Mississippi and all its tributaries form a fifteen-thousand-mile web of waterways stretching from present-day New York to Montana, through nearly half the lands of the continental forty-eight states. Its shallow valley is so broad, a traveler once said, that "a native tribe from its eastern rim of the Alleghenies might spend a generation migrating through it before sighting the Rockies that walled it on the west."

The river came to be called "Father of Waters," but in geological age it was barely a toddler, and a defiant one at that.

It sprang into being as the glaciers of the last Ice Age lumbered northward, trailing swampy streams that became the Ohio, the Missouri, and a hundred others. Where these streams joined and ran south to the ocean, they dug a groove through the soft slab of clay and sand that became the American South. Every year, every droplet of spring rain that fell upon much of the continent ran downhill in the direction of that groove -- the Mississippi's riverbed -- each rill carrying a microscopic load of organic material and sand. Coursing southward, the water scoured more soft earth from the banks and bottom and whisked it along. Below the points where the Missouri and Ohio joined the master stream, uncounted tons of dirt swirled in the water like muddy clouds. (Farmers would say it was too thick to drink and too thin to farm.) The water and its burden of sediment determined the river's ever-shifting geography, and the geography challenged the ingenuity of the Americans who settled on the banks.

They soon learned that the river, like a creature of myth, possessed the power to change its shape, and did so again and again. Wherever the current slows, especially on the inside curve of a bend, sediment falls to the bottom. There a sandbar forms. The bar nudges the oncoming current toward the opposite bank. That bank crumbles under the current's pressure, sending more sediment downstream, where it collects elsewhere as a new sandbar. Mile after mile, century after century, the river undulates in a crazy squiggle of curves and horseshoes.

This process of geological transformation handed Henry Shreve his great challenge. In his era the trees of the original North American forest still stood guard up and down the Mississippi. Wherever the current assaulted the banks, these old giants lost their footing, slid into the river, and floated downstream as dangerous snags. Some blundered into sandbars or islands, catching other snags and blocking the watercourse. Some wandered free, their bobbing limbs beckoning to rivermen in slow, sinister gestures of invitation. (These were called "sawyers," for the way they appeared to saw the surface.) The deadliest snags were called planters -- trees whose roots caught in the silt floor and stuck fast. More silt would pile against the roots, embedding the tree, its shaft pointing to the surface like a battering ram. When a steamboat struck a planter, the murderous effects were instantaneous -- "a sudden wrench, the rush of sucking water, a clanging of bells, terrified screams, and the current would sweep over another tragedy."

The snags had been falling into the Mississippi since the Mississippi began. The early French settlers at New Orleans had called them chicots -- "teeth of the river." By the 1820s, American surveyors counted 50,000 of them. And those were only the ones they could see. As steam traffic mounted, so did the damage and loss of life. Fear of snags slowed commerce. Military men, including Generals Andrew Jackson and William Henry Harrison, said snags impeded their mobility in the War of 1812 and the Indian campaigns. Pleas for federal action rose. In the summer of 1818, the influential Niles' Register reported: "Three steam boats have been lost in five months...in consequence of running foul of great trunks of trees....Will not the increased navigation of this mighty stream soon justify an attempt to clear it of such serious incumbrances -- or is it practicable to do it?"

That was the question: Did any effort to clear the Mississippi of 50,000 snags even stand a chance?

Henry Shreve believed so. As an owner of steamboats, he found the sodden driftwood hindering his every trip, costing him money and threatening the safety of passengers and crews. The great logs became a personal challenge, even a mild obsession. At home and on the river, he sketched plans for a strange new river craft.

Then, in 1824, the glowering South Carolina statesman John C. Calhoun, as secretary of war, invited river men to submit ideas for snag clearing. Shreve offered his plan for a twin-hulled steamer rigged with an apparatus for sawing off snags underwater and hauling them out with a manually operated windlass. Calhoun never responded. Yet no other river man produced a practical idea.

Soon a second plea issued from Washington. This time Shreve kept quiet, and the War Department hired John Bruce, a Kentuckian like Shreve, to clear all snags from the Ohio and the lower Mississippi for $65,000. Bruce tried his own twin-hulled design, failed, then attacked the Ohio snags with teams of men armed only with saws and chains. After two years they had barely begun on the Ohio, let alone the Mississippi, and Bruce's money was gone.

Under increasing pressure from the West, the new secretary of war, James Barbour, cast about for some new plan. He spoke to Calhoun, now John Quincy Adams's vice president, who recalled Shreve's ideas. Though Shreve was well-known as an Andrew Jackson man -- and thus a natural enemy of Adams, who had defeated Jackson for the presidency in 1824 -- the administration set aside its partisan reservations and hired Shreve as superintendent of western river improvements under the army engineers, at a salary of six dollars per day.

Shreve had to send a stream of beseeching letters before Washington would authorize construction of his snagboat for $12,000. Finally, after he reported success with a model -- "The machine is beautifully simple and most powerful in its operation and produces the effect intended in the most admirable manner" -- the army agreed to pay, but told Shreve that if his experiment failed, he would bear the cost himself.

At New Albany, Indiana, a few miles down the Ohio River from Louisville, Shreve's idea took on solid form. Two steamboat hulls 125 feet long lay side by side, each with a paddle wheel on its outer edge. Beams connecting the hulls supported an overhead pulley-and-windlass apparatus for lifting snags from the water. At the bow was a wedge-shaped beam made of heavy timber and sheathed in iron. This was the weapon Shreve would thrust at snags. He named the boat Heliopolis.

Few on the rivers believed it would succeed. Some even stooped to political sabotage. A fellow river captain wrote the War Department: "It is said that the present Superintendent has it in contemplation to construct a large and powerful steamboat, for the purpose of cutting out the snags, and pulling them out by the force of steam. Now, those projects are only calculated to get through the appropriation, without anything like the object contemplated. All machinery, whatever, whether used by lever or steam power is considered by persons who are well-acquainted with the Mississippi river navigation, as a useless expenditure of time and money." But other captains signed petitions on Shreve's behalf. They wanted action against the rotting obstacles, however unlikely the result.

In the spring of 1829, the Heliopolis was finished. But a drought had drained the Ohio to its lowest level in years, keeping Shreve in port. He waited. In mid-August heavy rains fell and the river swelled. The Heliopolis made its way down the Ohio, then the Mississippi, to Plum Point, Tennessee, a place studded with snags, one of the most dangerous places on the entire river. Shreve arrived at midnight on August 19.

In the morning, as he got ready, other boats stood at a distance, their crews expecting the first collision with a snag to jolt the snagboat's boilers into explosive fury. Shreve chose a planter and turned the boat toward it. The Heliopolis gathered speed and closed in. At full steam the iron wedge crunched into timber. The tree snapped. Windlasses whirled and chains clanked, and the planter emerged, dripping, from the brown depths. The trunk had broken several feet below the surface of the sandy bottom. In moments, Shreve's men sawed it into small pieces.

That fall Shreve roamed the western rivers. By 1830 his triumph was known throughout the country. "Capt. Shreve has perfectly succeeded in rendering about 300 miles of river as harmless as a mill-pond," one newspaper reported. A second snag boat was commissioned, then a third and fourth, all virtually identical to the Heliopolis. Soon the Ohio and Mississippi were all but free of snags, then the Arkansas. Finally, in his most remarkable achievement, Shreve cut through the immense log blockage of the Red River in Louisiana known as the Great Raft, 150 miles long, all the way to a place that would soon be called Shreveport. From Texas to Pennsylvania, the rivers were clear.

Of course, even a clear river is only as safe as its channel. Shreve's ingenious boats had made the river safe during normal seasons. But the Mississippi is capable of frightening departures from the normal.

AN ENDLESS WALL

[Y]ou hardly ever see the river, but the levee is always close by, a great green serpent running through woods, swamps, and farms, with towns nestling close to its slopes. The levee is unobtrusive, since its slope is green and gradual, but in fact it is immense -- higher and longer than the Great Wall of China, very likely the biggest thing that man has ever made....It was the principal human response to the titanic power of the great river.

-- Alan Lomax, The Land Where the Blues Began

A band of mosquito-ridden Spanish soldiers were the first people of European origin to see the Mississippi in flood. In 1543 they crossed a bewildering inland sea that drowned all but the tallest trees, and they paddled like hell to leave it behind.

What they saw was simply the lower Mississippi being its natural self. The river rises with the rains every spring and often spills out on the land. Through the millennia since the last Ice Age, the spreading floodwaters have dropped layer upon layer of sediment, the heaviest sediment nearest the river, thus creating a rich cake of soil up and down the banks. The land sloped away from these natural mounds and turned swampy, but under the swamps the land was highly fertile, too.

The French, who came a century and a half after the first Spanish explorers departed, weren't so easily scared off. They built a town, New Orleans, on the broad mound of sediment between the river and Lake Pontchartrain. To keep the spring high water out of their streets, they constructed a dike along the river. They called it a levée, from the verb lever, to raise. By 1727 it was three feet high, eighteen feet across the top, and a mile long. If they had known what Herculean labors they were setting in motion by building that little wall, they might have packed their bateaux and followed the Spanish. For one levee inevitably begat another levee, and so on ad infinitum.

This the Americans discovered soon after President Thomas Jefferson bought the vast, unexplored territory of Louisiana -- essentially the entire western drainage basin of the Mississippi -- from the French in 1803. They learned that if you built a three-foot-high levee on the east bank of the river, while on the west bank there was no levee, then the next flood crest would overflow the west bank. So the people on the west bank would build a six-foot levee and push the next flood back to you. The logic became obvious: Wherever people proposed to live year round, there must be levees.

At first, planters along the river bore the expense of building the mounds on their own land. But as it became clear that the levee was only as strong as its weakest section, and as costs mounted, levee districts were organized and given the power to raise taxes that would spread the financial burden among all those who benefited from the levee's protection. In some years, such as 1828 and 1844, high waters broke through the walls to flood farms and villages. But in most years the levees worked. They protected existing farmland and made it possible to drain and plant new farmland. More people came, and they depended on the levee, too. And so it went on both sides of the river, foot by foot and mile by mile.

By 1850 the costs were crushing. Under pressure, Washington bequeathed millions of acres of federal swamplands to the riverine states, which then sold the land to raise money to build more and better levees, which meant that still more swamps could be drained to make farms, and still more people depended on the levees.

As the levees became indispensable, their construction became more sophisticated. The early levee builders had simply piled dirt on the riverbank in long mounds filled with stumps and logs. A major high water could easily shove many of these mounds aside. Or the water, soaking the levee, would cause the stumps and logs to rot, leaving cavities that collapsed under pressure. Gradually, civil engineers learned the river's destructive tricks and how to combat them, and by 1880 they had developed a standard levee design.

First, workers would clear all debris from a wide ribbon of space, usually well back from the river itself. Down the middle of this space they dug a ditch three feet deep and three feet wide. They refilled the ditch with fresh dirt, then piled a mound of dirt on top of the dirt in the ditch. By this process they created one solid mass of material, some below ground and some above, with the ditch dirt anchoring the levee to the natural ground as the whole mass compacted and hardened. The river couldn't so easily push this anchored mass aside.

The levee was to be 3 feet taller than the presumed high-water maximum. The base at ground level was to be 5 to 7 feet across for every foot of vertical height. The levee should be as wide at the top as it was high. Thus, as the levee grew taller, it grew much broader. A levee just 7 feet high would be 7 feet wide at the top and 35 to 50 feet across at the base. After another ditch was dug to lure away the water that inevitably oozed through the structure, workers seeded the whole mound with Bermuda grass, which in time formed a tough, soddy seal that withstood high water far longer than exposed ground.

These rough engineering works were hardly perfect. Men had to patrol the levees to spot trouble, especially in spring. They looked for animals, even crawfish, digging tunnels through the mounds. They looked for sand boils, the little geysers that erupted when the river's colossal weight pushed jets of water under or through the levee, eroding it from within. And in flood times, the guards watched the river for men approaching by boat with explosives. If they blew a hole in your levee, inviting the river to destroy your land, they might save their own.

And the river did increasingly hold the power of destruction. For the levees were built on a paradox. The higher they rose, and the more continuous their line on both sides of the river, the more protection they afforded -- as long as they did not break. If they broke, their great height actually increased the risk that the ensuing floods would drown and destroy.

Why? Because untold millions of tons of spring floodwaters now stood much higher -- nearly forty feet high in some places -- than the ground on which the levees were built. When that much water stood so high above the land and then tore a hole, or "crevasse," in the levee, simple gravity would force the water to fall on the land with a force akin to Niagara Falls.

Engineers on the River

Whenever the levees failed, the people of the lower Mississippi begged the nation's engineers for solutions. But to tame the river the engineers had to understand it, and its behavior was nothing short of bizarre.

As John M. Barry wrote in Rising Tide, his comprehensive study of the control of the lower Mississippi and the 1927 flood, the river "moves south in layers and whorls, like an uncoiling rope made up of a multitude of discrete fibers, each one following an independent and unpredictable path, each one separately and together capable of snapping like a whip. It never has one current, one velocity. Even when the river is not in flood, one can sometimes see the surface in one spot one to two feet higher than the surface close by, while the water swirls about, as if trying to devour itself. Eddies of gigantic dimensions can develop, sometimes accompanied by great spiraling holes in the water." Where the watercourse bends, "the collision of river and earth...creates tremendous turbulence: currents can drive straight down to the bottom of the river, sucking at whatever lies on the surface, scouring out holes often several hundred feet deep."

The river's variables were many and they changed constantly. Heavy rainfall or collapsing banks could shatter months of careful observations. The shape of the riverbed's underwater cross section varied wildly from place to place. Tidal waters entering from the Gulf of Mexico affected the river's movements for many miles upriver. At flood stage the river behaved entirely differently than at low water. Levees that held a large high water might collapse under a lesser one. And hard as it was for the engineers to detect any predictability in the water itself, it was perhaps even harder to perceive rhyme or reason in the behavior of sediment -- how it moved at various depths, why it fell to the bottom where it did, how it affected the speed and direction of the current. Whenever one set of conditions seemed about to yield to sustained study and analysis, the river would blast those conditions to hell and make something wholly new and unknown.

In the mid-1800s, two schools of thought gradually emerged about what to do. Given the scarcity of dependable fact, it's hardly surprising that they seemed to be diametrical opposites.

One school argued that the river could be enlisted to dig itself a deeper bed, which would hold more water and thus prevent floods. The theory had its roots in the valley of the Po River in northern Italy. There, an engineer named Domenico Guglielmini (1655-1710) had theorized that if you built walls to confine an alluvial river such as the Po, you would force the river to rise. A higher river has a steeper slope to its outlet, and a steeper slope makes the river run faster. A faster river scrapes up more sediment from its bed. In short, a river confined within levees would dredge a deeper bed for itself, and thus carry more water in times of flood. The "levees-only" theory, as it was known, scored some successes in controlling floods in Europe, so it gained adherents in the Mississippi valley. Some even argued for closing off the Mississippi's natural outlets to increase the river's scouring power. But they had fierce opponents who believed levees were little more than a necessary evil.

The idea of the opponents of "levees-only" can be expressed by analogy to a kitchen sink. When someone closes the drain and turns on the faucet, water climbs up the walls of the sink. If no one opens the drain or turns off the faucet, the water overflows onto the floor. That is the nature of rivers, too, but no one can turn off the Mississippi. If you can't turn off the faucet and you don't want the floor to get wet, it doesn't make sense to build up the walls of the sink. It makes sense to open the drain.

To keep the Mississippi from flooding, the opponents of "levees-only" said, its drains must be kept open. Dredges should be employed to keep silt out of the river's natural outlets, such as the Atchafalaya River and other Louisiana bayous, so they could better absorb floodwaters. Reservoirs should be built on tributaries to hold floodwaters out of the main river. And most important, artificial outlets should be built to allow floodwaters to spill off into alternative routes to the Gulf. These ideas comprised the "outlets" theory of flood control.

To resolve the argument, Congress decided in 1850 that a major federal survey was needed to wrest the secrets of flood control from the lower Mississippi once and for all. Because this was to be one of the great scientific undertakings of the era, leaders of the Army Corps of Engineers assumed the survey would be theirs. After all, the profession of engineering in America had been virtually synonymous with the corps for half a century; few influential engineers had been trained outside West Point. But as the industrial revolution spread, engineers outside the military were rising in numbers and influence, and they demanded the Mississippi survey be assigned to one of their own. So President Millard Fillmore simply split the $50,000 appropriation in half and told the army to do one survey and the civilians another.

The civilian effort fell to Charles Ellet. One of the first American engineers to spurn West Point, Ellet took his training at the more scientific école des Ponts et Chaussées, in Paris. Handsome, brilliant, and brave to the point of foolhardiness -- he was the first person ever to cross the gorge at Niagara Falls -- Ellet commanded respect. He compiled his report in under two years. Short on data but long on vision, the report called levees-only "a delusive hope, and most dangerous to indulge, because it encourages a false security....The water is supplied by nature, but its height is increased by man. This cause is the extension of the levees." Instead, Ellet called for the dredging of natural outlets and the construction of artificial ones. For a few years in the 1850s, his work was celebrated as the authoritative statement on the Mississippi.

His rival in the corps of engineers was Andrew Atkinson Humphreys, a driven and driving man who, despite his army background, approached the study of the river with far greater scientific tenacity than Ellet. This meant that he took longer than Ellet. He chased every last fact, tested every theory. He became so consumed by his task that he suffered a nervous breakdown, lost his funding, and had to set the work aside for several years. But in the summer of 1861, amid the first clashes of Union and Confederate armies, Humphreys completed his survey. It became the most influential scientific study of the Mississippi ever written.

Humphreys was no more persuaded by the levees-only theorists than Ellet had been. Observable facts proved Guglielmini's idea that levees would lead to a deeper river "totally erroneous," Humphreys said, and that closing natural outlets would be "disastrous."

But Humphreys was equally dismissive of the outlets theory. He said flood reservoirs on the Mississippi's tributaries would not work. He said artificial outlets, though they would indeed lower the river, would be too expensive relative to the value of the property they would protect. And, he said, outlets posed a grave, heretofore unforeseen danger. In a great flood, the main stream of the Mississippi might shift entirely to the new outlet, leaving the old channel, with all its human settlements, an isolated backwater. To guard against floods, he said, the nation would have to make do with strong levees. They would not make the river deeper, but they "may be relied upon for protecting all the alluvial bottom lands liable to inundation."

The Civil War distracted all attention from river hydrology. But it decided the winner of the great river debate. Charles Ellet was killed on a Union battering ram. Andrew Humphreys not only survived the war but achieved renown as a field commander at Fredericksburg and Gettysburg. To reward his war service and his river survey, he was named chief engineer of the army in 1866.

Ellet's case for outlets faded away, and Humphreys's views prevailed. Unfortunately, the nuances of his massive report were not entirely understood. People understood him when he said levees would do the job. But many overlooked his dismissal of the key idea of levees-only -- that levees would make the river deeper. So the levees-only theory lingered in the public mind. And in the 1870s it appeared to draw new vitality from the extraordinary achievement of a brilliant, disciplined, austere man who was regarded as the nation's greatest engineer, James Buchanan Eads.

Mr. Eads at the Passes

Eads had learned the Mississippi's strange ways as no man ever had. In 1838, as a steamboat man barely out of his teens, he had spotted opportunity in the hundreds of shipwrecks sent to the river bottom by fires, boiler explosions, and Henry Shreve's snags. Some said the river's crazy currents and shifting floor made it impossible to salvage the wrecks. Eads disagreed. He built a salvage vessel much like Shreve's snagboats. To locate lost cargos in the silt-laden water, he made some three hundred descents to the bottom in dangerous diving bells. About one dive he wrote:

"The sand was drifting like a dense snowstorm at the bottom....At sixty-five feet below the surface I found the bed of the river, for at least three feet in depth, a moving mass and so unstable that, in endeavoring to find a footing on it beneath my bell, my feet penetrated through it until I could feel, although standing erect, the sand rushing past my hands, driven by a current apparently as rapid as that on the surface. I could discover the sand in motion at least two feet below the surface of the bottom, and moving with a velocity diminishing in proportion to its depth."

These intimate explorations provided all the data that Eads's acute mind needed to master the river in various ways. He made a fortune in salvage. During the Civil War he constructed ironclad warships for the Union navy. After the war, at St. Louis, he built the first bridge over the Mississippi, proving the value of the new experimental metal, steel.

Even before his bridge was complete, Eads, now fifty-five years old, tackled a still greater challenge, this one in the deepest South, where the Mississippi splits into three short branches, or "passes," and flows into the Gulf of Mexico. What he accomplished there had nothing to do directly with flood control. But it would profoundly affect the flood control debate.

Here at the river's mouth lay muddy lumps of geological goo from every acre of land between the Pennsylvania coal fields and the Yellowstone wilderness. These great sandbars were growing noticeably larger by the year, slowing the passage of ships in and out of the river and threatening to block them entirely.

The sandbars were the natural product of the river going about its business. Every day the current dropped more sediment at the mouth. In time, when there was more sediment than water, the river in its nonchalance would simply spill off in some new route to the Gulf. It had done so for eons.

But Americans had committed themselves to this route, lining it with cities and farms and port facilities. They couldn't wait for a century as the Mississippi slowly changed its mind. The sandbars threatened the prosperity of the entire valley, even the nation. In 1859, a visiting business delegation counted three ships stuck on sandbars, thirty-five ships waiting upstream to get into the Gulf, and seventeen waiting in the Gulf to get into the river. Action was essential.

The corps of engineers failed in one attempt after another to get rid of the bars. In desperation, the New Orleans Chamber of Commerce demanded that a canal be dug to bypass the blockage altogether. The corps agreed. Ships still would have to stand in line, because the canal would be wide enough for only one ship at a time, but at eighteen feet it would be deep enough for most ships. It would cost $13 million. The canal's champion was the corps's chief engineer, General Andrew Humphreys.

With the canal plan all but settled, James Eads entered the debate. Nearly forty years earlier, Eads had been working in St. Louis when huge sandbars rose up between the city's waterfront and the river. Eads watched as a young army engineer carried out an ingenious plan. At a strategic point in the river, the officer constructed a great pier, or jetty. The jetty guided the river's currents directly against the sandbars. The sandbars washed away and the threat to the city disappeared. The young officer's name was Robert E. Lee.

Eads had not forgotten. Since then, he had seen jetties clear out the mouths of European rivers, and he had only contempt for the corps's planned canal. So Eads proposed to build a pair of parallel jetties in the southwest pass of the Mississippi. The jetties, he said, would squeeze the river's spreading currents like the nozzle of a firehose and blast the sandbars into the Gulf. He promised that his channel would achieve a substantially greater depth than the corps was proposing for its canal. And he said it would be wide enough that ocean-going ships could pass each other in and out of the river. He could do the job for just $10 million, he said, and the government wouldn't have to pay until he delivered.

Humphreys and a phalanx of critics lashed back. All through the spring and summer of 1874, Eads and Humphreys battled for support in Congress, lobbying, cajoling, arguing, lecturing. Newspapers across the country covered the fight. Civilian engineers supported Eads, hoping to take the corps of engineers down a peg. Humphreys had the backing of New Orleans's business elite. These men distrusted "strangers" like Eads, "who can know nothing of our inexorable enemy," the river, which would teach such upstarts "modesty and humility in the presence of the gigantic torrent."

"I am sure I have not learned 'modesty and humility in the presence of the gigantic torrent,'" retorted Eads, who had spent far more time in the Mississippi -- literally -- than any New Orleans tycoon. "Nor do I believe that it can be controlled by modesty and humility."

After more months of study, a committee of experts appointed by Congress recommended jetties by a vote of six to one. But General Humphreys devised a trap. His friends in Congress insisted that Eads switch his plan to the shallower South Pass -- this would be cheaper but more difficult -- and when Eads argued, they said he was trying to extract excessive profits from the deal. Eads was forced to accept the South Pass plan.

Defiant, he promised victory.

"If the profession of an engineer were not based upon exact science, I might tremble for the result," he said. "But every atom that moves onward in the river, from the moment it leaves its home amid crystal springs or mountain snows...until it is finally lost in the vast waters of the gulf, is controlled by laws as fixed and certain as those which direct the heavenly bodies....I therefore undertake the work based upon the constant ordinances of God Himself; and [if] he will spare my life and faculties for two years more, I will give the Mississippi River...a deep, open, safe and permanent outlet to the sea."

In May 1875, Eads set off from New Orleans with a fleet of barges, tugboats, steam launches, and floating pile drivers, all bound for the low-lying landscape where little but whispering grasses and fishermen's huts marked the presence of land in a wilderness of water and sky. They found the sand-clogged South Pass only eight feet deep.

First Eads's men built a settlement of white cottages and plank walks, which they called Port Eads. Then they drove two lines of piles -- log posts like telephone poles -- deep into the river bottom. These parallel lines of piles stretched about two miles long, about a thousand feet apart. They marked the lines of the two jetties.

Eads had dropped off some of his crews forty miles upriver, where they waded among water moccasins and leeches to cut thousands of young willows. They sent the trees by barge to Port Eads. There other crews heaped the trees in pine frames to make giant, brushy "mattresses," each 100 feet long, 35 to 60 feet wide, and 2 feet thick. Dutch dike-builders had invented these odd contraptions, but Eads's method cut the time it took to build one from two days to two hours. When each mattress was finished, a tugboat towed it to the jetty pilings, where men dumped rocky rubble on it, forcing it to sink. Then another mattress was sunk on top of the first, and so on until the mattresses stood up to sixteen layers deep.

Section by section, these towers of sunken willow mattresses formed the jetties' walls -- or, more accurately, they formed a dense scaffolding for the walls. The river completed the job, just as Eads had foreseen. Gradually the passing currents deposited sediment on and among the mattresses, filling in the jetties until they were as solid as concrete.

But before he could prove the jetties were deepening the channel, Eads ran short of funds. Humphreys's men on the scene conducted their own depth soundings and claimed the channel was only 12 feet deep -- far short of the 30-foot requirement -- and that the jetties had created "the nucleus of a new bar" farther out in the Gulf. Eads's own soundings showed the channel was at least 16 feet deep already, and that the sandbar was a mirage. But federal officials refused to issue the official report of soundings, or to order new ones. Without this official proof Eads would be unable to attract new investors, and his whole endeavor would collapse.

Then, on May 12, 1876, the big oceangoing steamer Hudson, with a draft of fourteen feet, seven inches, approached the mouth of the river from the Gulf. Its captain was E. V. Gager, a friend of Eads and a supporter of the jetty plan, who had said he hoped his ship would be first through the new channel. Learning what was at stake, Gager, despite a falling tide, ordered his vessel onward.

James Eads had told him the channel was sixteen feet deep. So Captain Gager ordered his engines put to full steam. Pushing a half-crown of white foam before her, the Hudson entered the channel...kept moving...steamed through.

"Captain Gager...greatly assisted the enterprise in one of its darkest hours," Eads's chief assistant wrote later, "for the stubborn facts brought out by his brave action could not be gainsaid."

Investors returned and the project was saved. By that fall the channel's depth reached 20 feet. In 1879 it was 30 feet. Soundings found no new sandbar rising in the Gulf of Mexico. In the five years after Eads began, the tonnage of cargo moving from St. Louis through New Orleans to Europe increased sixty-six fold.

"Human patience and courage and industry, backed by an indomitable and untiring will, and informed and directed by human skill, have applied the force of nature to the accomplishment of an end too vast for mere artificial agencies," a New Orleans editorialist wrote. "Man has used the tremendous river which uncontrolled has been its own oppressor and imprisoner, and has now become its own liberator and saviour."

THE WATER RISES

Eads had made the Mississippi do his bidding with a work of engineering that became famous around the world. That was good and bad. For some people now lost a little of that "humility in the presence of the gigantic torrent" that the Mississippi demanded. They believed Eads's jetties confirmed the levees-only theory of flood control.

Eads himself believed nothing of the kind. He said levees would never cause an appreciable deepening of the riverbed because they stood back from the banks, and confined the river only in flood season. Jetties, by contrast, were built right in the river. They didn't merely hold the current off the land. They concentrated it, increasing its power. And they performed this feat year round. Nonetheless, people now thought levees, like jetties, would force the river to scour a deeper channel, which in turn would mean fewer floods.

Levees-only offered a political advantage, too. In the 1870s and 1880s, the levee system lay in ruins. In 1865 the corps of engineers had counted fifty-nine breaks in the levees in the Mississippi Delta alone. Demolition teams under General Ulysses S. Grant had done a good deal of the destruction. The river's natural powers of erosion, plus great floods in 1867 and 1874, did more. And the Civil War had impoverished the states of the lower Mississippi. Few levee districts could afford to do their work well.

Since the days of Jefferson and Jackson, Americans had believed that the Constitution forbade federal spending on projects that helped only one state or region. If Louisiana and Mississippi wanted protection from floods, the argument went, they would have to pay for it themselves. But interstate commerce was another matter. Everyone agreed that warranted federal help. If one argued that levees would aid interstate commerce by keeping the river deep and stable, one could persuade Washington to pay a big share of the bill. Flood control would be just an incidental benefit of better levees. On the other hand, the only argument one could make for floodways and reservoirs was in the name of flood control. If that was what you wanted, you had to pay for it yourself. Besides, the levees-only theorists said, reservoirs and spillways would only diminish the supposed scouring power of the river.

By 1879, it was clear that levee-building must be systematized and strengthened. So Congress -- in a delicate act of reconciling constitutional activists and conservatives, army and civilian engineers -- gave the job to a new Mississippi River Commission. Its powers were deliberately vague. Its membership was split between soldiers and civilians, but the soldiers soon gained the upper hand. They supervised a vast program of levee improvements, with new standards for construction and height. The levees rose higher and stronger.

But so did the river, contrary to the levees-only theory. By 1890, when yet another major flood inundated the valley, it was obvious the levees were not forcing the river to dredge itself a deeper bed. But the levees did offer short-term protection against devastation. Money was limited.

Better to spend it on bigger levees, which promised safety for next year, than on expensive and experimental works -- such as jetties or outlets -- that would take many years to produce results if they worked at all.

By the 1920s the levees stood unbroken from the mouth of the Ohio to the Gulf, a thousand miles on either side, three and four stories high, more than 400,000 cubic yards of earth for every mile of levee. Every spring, the rebellious river stood up on top of the land, running down the continent between two walls built by the hand of man.

The Great Flood

Late in the summer of 1926, storms drenched the Midwest. The rivers rose to levels unheard of so late in the year. The rain abated, then began again in January 1927, much earlier than the usual spring rains, in a wave of cataclysmic storms. Water rose so high at the confluence of the Ohio and Mississippi that the Ohio turned around and flowed upstream.

In April the rain grew worse -- eighteen inches on Good Friday in New Orleans, with similar inundations across the Midwest and South. The next day, April 16, the Mississippi broke through at Dorena, Missouri, flooding 175,000 acres. It was the first crevasse ever in a levee built to federal specifications. To steady a shaking railroad bridge over the Arkansas River, engineers parked a coal train on it. The trembling became so violent the coal erupted in flame, and the bridge collapsed, train and all, into the rushing water.

About 6:30 A.M. on Thursday, April 21, a stream of water one foot deep and two feet wide began to spurt through a low spot in the levee at Mounds Landing, Mississippi. Foremen held laborers at the spot at gunpoint, but the sandbags they threw in the hole spun away in the widening torrent. At 8 A.M. a massive chunk of the levee crumpled -- it "just seemed to move inward as if 100 feet of it was pushed out by the river," a witness said -- and the water rushed through, carrying scores of men to their deaths. People heard the sound miles away.

A virtual tidal wave surged east and south across the Mississippi Delta, its volume double that of Niagara Falls at flood stage. The water spread 50 miles to the east and 100 miles downriver at a depth of 20 feet, forcing nearly 200,000 people to flee. It struck a ridge of hills and turned south, rejoined the Mississippi near Vicksburg, and punched out the levee on the opposite side of the river, at Cabin Teele, Louisiana. From there the water rolled over a belt of land 50 miles wide, joining more rivers already in flood.

Mounds Landing and Cabin Teele were only the worst crevasses. There were 120 in all, 42 of them major. In some places the Mississippi stretched 100 miles wide. "For mile after mile all the land in view was the tops of the levees, to which thousands had fled for safety," wrote a reporter who crossed the inland sea in an airplane. "In places the tops of giant cypress and oak trees still swayed in the breeze, the only green spots in the picture."

All through early April, the 419,000 people of New Orleans had waited. The levees had protected the city from floods since 1849. Some students of the river now believed the immense power of the approaching flood crests actually worked to the city's advantage -- the water couldn't help but break through levees upriver. That would relieve the danger to the city. But the rising water carried its own logic, and thousands fled for higher ground.

During the Good Friday storm, a self-appointed committee of businessmen, most of them bankers, decided they would take no risks. The levee must be dynamited to bring down the level of the river. The river would have to be unleashed. They could break the levee upriver from the city, where much valuable property would be wrecked, or downriver, where the land and people were poor. They chose the latter. The mayor, the governor, the Mississippi River Commission, the chief engineer of the army, and the secretary of war assented. (Secretary of Commerce Herbert Hoover, supervising the flood relief operation and preparing to run for president, refused to add his approval and absolved himself of any responsibility for the decision.) Ten thousand residents of two marshy parishes between New Orleans and the Gulf -- St. Bernard and Plaquemines -- were warned to evacuate their homes. On April 29, thirteen miles below New Orleans, demolitionists blasted a hole in the levee at a place called Caernarvon, and the downriver parishes were flooded. Their losses made up only a fraction of the total in this greatest of all U.S. floods: 17 million acres inundated in seven states; $100 million in lost crops; 160,000 flooded homes; 250 to 500 people killed.

As it turned out, the deliberate destruction of the levee at Caernarvon was unnecessary. The next day, the river cut a new crevasse north of New Orleans, eliminating any danger to the city. But the Caernarvon explosions signaled official recognition of a truth that rogue levee dynamiters had sensed for decades. Artificial spillways lowered floodwaters. The policy of levees-only made floodwaters more destructive.

"The River Needs More Room"

As the slimy, stinking fields of the flood region slowly dried in the late summer and fall of 1927, engineers motored from crevasse to crevasse, looking at the broken levees and wondering at the river's power. The flood had been the worst natural disaster in the nation's history. A great debate arose over how to prevent a repetition.

Seated at his desk in the War Department in Washington, D.C., General Edgar Jadwin examined his data through strong spectacles. His eyes were weak, but at least they were fresh. Jadwin had been chief of the corps of engineers only ten months when the flood occurred; before that he had worked on more harbors than rivers.

At sixty he was brainy, small, and a bit frail. He was fiercely defensive of the engineers. But he did not have to overcome a career-long devotion to levees-only, as did veterans of the lost war against the Mississippi.

Finally Jadwin declared: "The river needs more room, which should be given to it laterally rather than vertically."

These words were not just the death knell of levees-only. They represented a radical change in belief. Americans could not simply make the river do whatever they wished. They must recognize its own implacable will and try to negotiate a compromise.

Under the Jadwin Plan, as it became known, levees would be repaired, strengthened, moved farther back from the river, and in some cases raised. But they would not be built to levels any higher than could safely contain the river. Waters above that safe level would be allowed to spill off through what were essentially manmade crevasses and manmade flood channels. The visionary engineer Charles Ellet, sixty-six years in his grave, would have his outlets at last.

Jadwin said his plan delivered "the maximum of benefits for the minimum of costs." Some minimum. It was the most expensive domestic legislation in U.S. history to date (about $300 million, and that was just start-up funding). It formed the foundation of all efforts to control the Mississippi for the rest of the century and beyond. It established a giant precedent for federal intervention in local and regional problems. And it helped elect a president: Herbert Hoover's 1928 campaign was based in part on his widely touted success in helping the river's victims in 1927, and on his support for federal action against floods.

The corps set off on a ponderous race against the yearly threat of another terrible flood. Year by year the work proceeded, unslowed even by the Great Depression.

The engineers designed their first project in the realm of nightmares. They combined history's worst flood statistics into a hypothetical "Project Flood" -- the greatest snowmelts in the upper valley, the worst rainfalls ever, simultaneous storms in distant parts of the Mississippi basin that would swell the tributaries to historic heights. These conditions, the corps said, would produce a flood 29 percent worse than 1927. All new works would be judged by their ability to protect the valley from "Project Flood."

At Birds Point, Missouri, where the Ohio tumbles into the Mississippi, the corps built a floodway five miles wide and sixty-five miles long to bypass a chokehold where there isn't enough riverbed to bear the combined flow of the Mississippi and Ohio in flood. A low, "fuse-plug" levee was built as a gate to the floodway. Only a major flood would blow out the fuse plug. Water would then flow into the floodway, run south, and rejoin the main current where the channel widens near New Madrid.

If floodways had been Ellet's pet idea, the corps borrowed other theories from James Eads. They built dikes at key points to stabilize the current. Between the mouth of the Arkansas and the mouth of the Red, they dug a straight path through a tortuous series of horseshoe bends, shortening the river by some 150 miles. (The longer the river, the more friction the water encounters along the banks. Friction slows the current and forces the river to rise higher on the levees.) These "cut-offs" were so successful they eliminated the need for an entire additional floodway.

Thirty miles above New Orleans, at a place called Bonnet Carré, the Mississippi had blown crevasses in the east bank levee again and again, streaming across seven miles of field and semitropical swamp to reach Lake Pontchartrain, a natural outlet to the Gulf of Mexico. Since 1816 people had been saying it made sense to let the river have its way here. The 1927 flood demolished opposition to the idea, and a spillway at Bonnet Carré was incorporated in the Jadwin Plan.

Using a giant laboratory model to test their plans, corps engineers designed a spillway that closely resembled an irrigation dam. This would not be a fuse-plug structure like Birds Point, designed to give way under the pressure of high water. Instead, engineers would carefully control the water flowing through it. Set back from the river, the spillway would run parallel to the riverbank for a mile and a half, with some 350 gates made of rough-hewn timbers called "needles." When a dangerous flood crest approached, cranes could pull needles up and out of the spillway -- as many or as few as necessary. These gates, once open, would skim the crest off the river.

But that carried its own dangers. Floodwaters would plunge through the gates with monumental force, gouging a canyon in the earth. So engineers found ways to calm the water down. On the side of the spillway away from the river, they laid a broad, low apron of concrete called a stilling basin. Here the water would crash into a big belt of triangular baffles that looked like waist-high dragon's teeth. These would dissipate the water's energy without blocking the flow. Beyond the baffles, the water would cascade onto a concrete mat that resembled a giant waffle. Its channels would further subdue the flow, and the water, robbed of its power to destroy, would run more or less placidly down the seven-mile slope to Lake Pontchartrain.

By early 1931 constructions teams finished the spillway. It was a structure to overwhelm the eyes; one could see the whole thing only from the air. Then they built bridges to carry two rail lines and a highway over the long floodway to the lake. Finally they raised a fuse-plug levee at the edge of the Mississippi, across the spillway's front, and covered it with Bermuda grass sod.

In December 1936 the entire structure was declared complete. By Christmas it was raining in torrents up and down the Mississippi valley. The annual high waters had spared the valley for ten years. But now the sod on the spillway levee would not take root before Bonnet Carré, and the rest of the Jadwin Plan, met its first test.

Soon a flow of 1.85 million cubic feet per second was recorded on the Ohio at Cairo, a spectacular high water. The engineers of the corps watched intently as the water surged against the new fuse-plug levee at Birds Point. When it failed to break, they dynamited it. That saved Cairo. As the crest moved south it caused small floods in backwater regions, but the strengthened levees on the main river held.

At Natchez, Mississippi, two hundred miles north of New Orleans, the flood gauge recorded its highest level ever. The same thing happened at Carrollton. That was the official trip-hammer for Bonnet Carré. The corps gave the word.

On February 18, 1937, with crowds watching, the cranes atop the spillway hoisted timber needles out of 285 of the 350 bays. Water rushed into the stilling basin and exploded through the baffles. Surging down the floodway toward the lake, the tide wrenched trees from the soil. Yet even that degree of force lay within the margin of safety. For one week, then two, the Carrollton gauge stayed steady, and New Orleans stayed dry. By March 7 the river was falling, and the corps began to reinsert the needles. Nine days later the spillway was closed.

The 1937 high water was not the Project Flood. But it was high enough to prove Bonnet Carré a signal success, and to show that the Mississippi might tolerate man's effort at a compromise. Not a single levee on the lower Mississippi failed in the 1937 flood, nor has any failed since.

A PATIENT RIVAL

If the Mississippi is a toddler in geological age, the Atchafalaya (uh-CHAFF-uh-LIE-uh), which connects to the Mississippi via a manmade waterway some 120 air miles northwest of New Orleans, is a newborn infant. It emerged from the swamp in the 1400s, carrying water from a horseshoe bend in the Mississippi (later called Turnbull's Bend) through a jungle labyrinth to the Gulf. To complicate the landscape, the Red River emptied into Turnbull's Bend a few miles north of the Atchafalaya. To help steamboat traffic, Henry Shreve dredged a cut-off canal through Turnbull's Bend in 1831. But one seven-mile arm of the bend -- soon called Old River by the locals -- remained to connect the Mississippi to the Atchafalaya.

The Atchafalaya is what geologists called a "distributary" river, meaning it carries water out of a larger stream. But a distributary can become a trickster and a thief. As the main stream rises atop its floor of silt, it sends more and more runoff spilling down the distributary. That runoff water gradually digs the distributary a deeper bed. In time, the distributary offers a deeper, steeper outlet to the sea. One big flood and the main stream may change its mind entirely. Suddenly the old channel is abandoned and the river is following the distributary's path to the ocean.

Over the eons this has happened repeatedly at the Mississippi's mouth. At least five now quiet bayous have all served their time as the main channel. The last shift occurred about A.D. 1000. If the Atchafalaya were to capture the Mississippi now, the Port of New Orleans, one of the world's busiest, and a multibillion-dollar belt of riverfront industry would be stranded on a brook.

River engineers saw this coming. Just after the 1927 flood, Colonel Charles Potter, president of the Mississippi River Commission, looked over the big river and its eager distributary and said the Mississippi was "just itching to go that way."

But the corps of engineers could hardly wall off the Atchafalaya, which was by far the most important outlet envisioned in the Jadwin Plan, much bigger even than Bonnet Carré. Plug the Atchafalaya and you not only devastate the fisheries and Cajun communities that depend on it for water, you also doom New Orleans in the next great flood. Yet every gallon of water spilling into the Atchafalaya dug its bed a little deeper and raised the likelihood of an eventual shift. By 1950, geologists said the slope of the Atchafalaya's path to the Gulf had become three times steeper than the Mississippi's current channel. The river, they said, would certainly shift from one to the other by 1975.

So the corps constructed another compromise. Earthmovers dug a new, seven-mile-long channel -- a new Old River -- between the Mississippi and the Atchafalaya. Across this channel the corps built a 566-foot version of the Bonnet Carré spillway. They called it the Old River Control Structure, usually shortened simply to "Old River Control." Engineers raised its gates just high enough to allow 30 percent of the Mississippi to enter the Atchafalaya. That was judged to be enough but not too much. In the Atchafalaya swamps, the corps constructed a system of floodways, chiefly the West Atchafalaya Floodway and, thirty miles to the south, the Morganza Floodway. Then, in 1963, the engineers blocked the old Old River, opened the new one, and watched water cascade through the carefully calibrated gates of Old River Control.

Through the 1950s, '60s, and early '70s, the Mississippi cooperated. The spring high waters were manageable.

Early in 1973, major storms raised the Missouri and the Tennessee to towering levels. The crest approached.

"This is not a routine high water," General Charles Noble, chief engineer of the corps's Lower Mississippi Valley Division, warned. "We are confronted with river conditions which, if not controlled, could cause more loss of life and property than this valley experienced in the 1927 flood."

Corps engineers watched the water pound through Old River Control. On April 8, for only the fourth time in its history, they opened the Bonnet Carré spillway downriver. Yet people standing on the 200,000-ton structure at Old River felt it shake.

As the journalist John McPhee told it, a fisherman came into the office of LeRoy Dugas, who manned the controls at Old River, and asked: "Is that south wall supposed to be moving like that?"

"What do you mean?" Dugas asked.

"On the control structure," the man said, "a wall on the other side is moving."

"No," Dugas replied. "It's not supposed to be moving."

Soon that wall gave way and crumpled into the Mississippi. On the Old River side of the structure, the water seized seven-ton boulders and hurled them downstream. Unseen below the roiling surface, mad currents were digging a hole the size and shape of a football stadium, and scouring cavities under the structure itself.

The corps waited a little while longer, then for the first time opened the gates of the new spillway downriver at Morganza.

Old River Control held -- barely. If it had collapsed, engineers believe 70 percent of the Mississippi would have run down the Atchafalaya slope. The struggle to keep the river in its old channel would have been lost.

Humility and Ingenuity

Scientists at Louisiana State University declared in 1980 that a shift in the Mississippi's course remained "simply a matter of time." But the people who lead the U.S. Army Corps of Engineers are professional soldiers. They do what their country tells them to do, whatever the odds, and their country has told them to keep the lower Mississippi where it is. So in the wake of the great scare of 1973, they went back to work at Old River.

Corps workmen drilled holes through the damaged control structure and pumped truckloads of cement grout into the cavities underneath. Into the cavernous craters just beyond the structure, they dumped 185,000 tons of rock. That was enough to hold the structure in place, even when another major flood rolled through in 1983. A few hundred yards away, the corps built an Old River Auxiliary Control Structure. Costing nearly as much as the original expenditure for the entire Jadwin Plan, it comprised 7 towers and 6 gates, each 62 feet wide.

"I was asked, when I was testifying before Congress about the auxiliary structure at Old River, if this improvement would be all that was ever needed there," recalled Fred Bayley, former director of the corps's engineering division for the Lower Mississippi Valley District. "And my reply was, 'No, sir.' And the next question was, 'Well, what will be the next thing?' I said, 'I don't know, but with the system we're living in out here, there will be something, and that you can count on and that you must ever be ready for.'"

Corps scientists sought new approaches to their great problem. They turned their attention to a phenomenon that James Eads had discovered firsthand more than a century earlier, under a diving bell -- the sand that "drifted like a dense snowstorm at the bottom." Sediment, after all, was the root of the problem. There was too much in the Mississippi and not enough in the Atchafalaya. If a lot of it could be moved from the former to the latter, the fatal percentages might shift back in the Mississippi's favor.

So a continuous dredging program was undertaken at Old River. Sand is scooped from the Mississippi's silt load and dumped into the channel that flows to the Atchafalaya. No one knows whether it will be enough. "Mother Nature doesn't holler back at you that quick," says a corps hydrologist. When that message comes, the corps will be listening closely. They know, as James Eads said, that "modesty and humility" will not control the river. But they have learned that a little humility is wise where the Mississippi is concerned.

When people came to live by the Mississippi, the struggle to control it became inevitable. Only nomads could live there if the river ran free, and Americans did not intend to be nomads. It may be true, as a historian of the corps of engineers once observed, that in the Mississippi valley, "nature might reasonably have asked a few more eons to finish a work of creation that was incomplete." But Americans are impatient. They would just as soon finish Creation on their own.

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The Epic Story of the Building of America, from th

Great Projects

The Epic Story of the Building of America, from th

Since the earliest days of the republic, great engineering projects have shaped American landscapes and expressed American dreams. The ambition to build lies as close to the nation's heart as the belief in liberty. We live in a built civilization, connected one to another in an enormous web of technology. Yet we have all too often overlooked the role of engineers and builders in American history. With glorious photographs and epic narrative sweep, Great Projects at last gives their story the prominence it deserves.

Each of the eight projects featured in this masterful narrative was a milestone in its own right: the flood-control works of the lower Mississippi, Hoover Dam, Edison's lighting system, the spread of electricity across the nation, the great Croton Aqueduct, the bridges of New York City, Boston's revamped street system, known as the Big Dig, and the ever-evolving communica- tions network called the Internet. Each project arose from a heroic vision. Each encountered obstacles. Each reveals a tale of genius and perseverance.

James Tobin, winner of a National Book Critics Circle Award, explains the four essential tasks of the engineer: to protect people from the destructive force of water while harnessing it for the enormous good it can do; to provide people with electricity, the motive force of modern life; to make great cities habitable and vital; and to create the pathways that connect place to place and person to person. Tobin focuses on the indi- viduals behind our greatest structures of earth and concrete and steel: James Buchanan Eads, who walked on the floor of the Mississippi to learn the river's secrets; Arthur Powell Davis and Frank Crowe, who imagined a dam that could transform the West; Thomas Edison, who envisioned a new way to light the world; Samuel Insull, the organizational mastermind of the electrical revolution; the long-forgotten John Bloomfield Jervis, who assured New York's future with the gift of clean water; Othmar Ammann, the modest Swiss-American who fought his mentor to become the first engineer to bridge the lower Hudson River; Fred Salvucci, the antihighway rebel who transformed the face of Boston; and J.C.R. Licklider, the obscure scientist who first imagined the Internet. Here, too, are the workers who scorned hardship to turn the engineers' dreams into reality, deep underground and high in the sky, through cold and heat and danger. In Great Projects -- soon to be a major PBS television series by the Emmy Award-winning Great Projects Film Company -- we share their dreams and witness their struggles; we watch them create the modern world we walk through each day -- the "city upon a hill" that became our America.

About the Author

James Tobin won the National Book Critics Circle Award in biography for Ernie Pyle’s War and the J. Anthony Lukas Work-in-Progress Award for To Conquer the Air: The Wright Brothers and the Great Race for Flight. Educated at the University of Michigan, where he earned a PhD in history, he teaches narrative nonfiction in the Department of Media, Journalism, and Film at Miami University in Oxford, OH.